Wrought Iron Railing into Stone?

OK I have to do a favor for my landlady. I'm furious, even though fair is fair. Dramatic story leading up to my question. Last year her church really needed to have the front masonry steps repaired. I volunteered to patch the steps and was sure it would hold up for a few years. So my landlady/friend told me no way, too much liability involved; it's got to be approved by the church board, etc. (So Ok I'll beg you to do you a favor I thought.) This is a little country church that doesn't have much money and it shows. (Tucked in right here in the middle of this swanky town, pretty old church.)

They ended up getting some imbeciles to completely rebuild the steps to the tune of five grand. Brick sides, 2" thick limestone steps. This staircase is about 8' wide about ten steps going up maybe six feet high to a front door.
My landlady's husband got somebody to repair the original wrought iron railing; and duplicate it so there are two primed railings waiting to be installed. But they can't get the guy to come around and install them. There are three legs on each that have to be anchored.
So my question is how do you attach wrought iron railings to limestone treads? I heard the masons split one of the treads trying to drill it. They had to replace it. I went there tonight to look, the masonary work is acceptable, really. One hole was apparent at the top of the stairs, and it didn't look clean, like somebody was chipping it out by hand Mayan style.
My idea is rent a drill with a 1 or 1-1/2" masonary bit and run holes to accept the steel square stock legs, and set them in hydraulic cement or mortar mix??? I heard they used to set them in lead, don't want to go through that. I'm set up to melt lead but there's got to be a faster way. There will be brackets at the top of the stairs which will help. I was also thinking of flanges to fit the square stock legs, and attach with metal anchors and four screws. I think they're 3/4 or 1".
I've seen many many old wrought iron railings corroded out at the bottom from contact with concrete! So I feel like I'm doing this under duress, but still want to do it right. Sorry for writing a novel here for one question.........

Use a boring bit, such as these. I got a 2" and a 4". I'll lone them to you. Then fill in with Acrylic-based mortor, which is pretty expensive, but WILL NEVER move.

dvc500 what do you turn that with how many rpms

looks like a sks drive. the smaller bosch hammer drils come with sks.

prolly a hose to flush out and cool might help.

the phone line men used to have a badd-azz epoxy they used in concrete mounting situations that would take full power phazers and photon torpedoes to hurt it. maybe with that 2 in core drill some
hi-tech epoxy would be easier than leading it in....

I think Chris is on the right path. If someone broke a tread with a hammer drill, then a diamond drill is the way to go. You might even turn off the "hammer" and have it work. Give thought to using epoxy to set them. They make some for the purpose. They used it in Boston to hold up the roof of the new tunnel and if had been used according to directions would not have failed. Besides, you're not asking it to hold a 5 ton slab to the ceiling. On the other hand, the acrylic motor would probably work very well and be much cheaper.

Yes, these bits are turned with an SDS-Plus drill. You can turn them with Hammer-ON or Hammer-OFF. Have someone hold a hose of water over the bit as you drill. 300RPM is fine.

Thanks guys. I looked around the internet for quite a while last night and couldn't find much other than a thousand wrought iron railing companies and dozens of articles on how to attach to wood decks....
My deal with my landlady is to fix everything around her house, not her church which is 1/4 mile away. Payback is a b****.
Off to Ho Depot to rent a phaser rifle....

Hey Chris, thanks for the offer to loan me the boring bits! I was just going to rent a rig at Home Trashpile, but they only had masonry bits. so I chased around the State of New Jersey to Clems Ornamental Railings, pretty big outfit; where they had cast iron railing flanges in a box right in the office. Too big but I wasn't chasing around no mo for this. I copped an attitude and felt this job was being done under duress, so I just got the flanges they had. One railing's legs are 7/8" and the other is 3/4" solid square stock legs. I got some anchors, drilled for the flanges and just butchered the whole job together. The limestone drilled like butter. There was so much slop between the leg and the flange that I lopped off some angle iron and put it in between. I caulked the bottom of the flanges and filled them up with marine epoxy. That ought to set em up solid. I made two braces on the outside to keep the railing taught.
Tomorrow I'll make the last brace, paint everything black and get out of there.

Looks good to me! There is a stud on each side, right? Cut the threads off flush with the top of the nut, so little kids can't cut their fingers, paint it all black, and your done! Miller time!

Yeah, not much sticking out; the concrete anchors are a little tricky, drill too deep and they don't leave much threads exposed. Got through it all anyway. I'll grind the studs flush and get some rustoleum on it all today. If I was a retired philanthropist I could keep busy forever at this place. The pastor is a nice enough lady, her husband doesn't seem to be handy...

Well, got done with that project today. They had the badly deteriorated stone steps replaced on that side, identical steps on the other side are cracking. The whole front porch of this church is blockwork, at least at the front wall, and it is cracking and separating. I noticed there is a six inch leader coming down from the massive church roof on that side, and I found where it comes out on the hill in front of the church. Another leader for the small front porch roof has been draining right straight onto the ground next to the foundation. There is no excuse for this kind of neglect, especially when there is a hill six feet away!!!!
On the side they just put the new steps in, there is a regular leader going into a 3" pipe that is set in the concrete work right next to the church. The new slab right next to it is cracked already. I couldn't find where it comes out on the hill! If it is plugged then there must be a huge amount of water trying to undermine the new stoop, slab, and small patio area made up of red pavers. The patio area pavers are spalled so bad it's ridiculous. They also have a crazy pipe rigged up for drainage from the back of the left side that spills out near the front of the church.
HAHAHAHA the pastor is probably inside preaching about building your house on sand.....
You wanna talk about rain harvesting? They could probably get 100,000 gallons a year off that roof.