I understand your situation. Next time I'm over I will stop for a look/see. I think the hopper is a very good idea, and adding an auger to the hopper makes more sense that reconstructing the missing pieces on your auger system.
You are now aware of how easy it is to fill the hopper, take out the ashes.....blah,blah,blah.
You just might like the situation you are working in. I have some of mine each way, but the hopper is less aggravation with an auger than the AA factory setup. Principally due to the issues with plugged tubes at the entrance....wet coal/fines issues. No problem with the hopper, but if you ever have to dig out a few tons to get at the doghouse, you will be a POed camper!! Yes, we all did it a few times, but make damned sure it doesn't happen again, ever!
It is the only way Keystoker makes a Boiler or Furnace......and they didn't just fall out of the Potato Truck!
It is the way Alaska, some Baker's, Harman, Hitzer, Leisure Line, Reading, and so on, make theirs. Glancing between the lines here I hope. Self feeding is wonderful, but overrated.
The 10 Million BTU Bio Mass boiler down the street is a masterpiece itself, but the auto feed is a piece of 's'. The engineer is from PA, perhaps a forum member, and he has revised the feed, rebuilt it this summer, and still it is a POS!
Imaging digging 30 tons of hardwood chips out of your way with an excavator.....inside an inclined bin about 60 feet long and 16 feet deep. Then try to work on a clogged feed mechanism, all bent up and jammed.....and it's a 7 digit number to buy this thing???!! Greenies UNITE!!! WTF!!!!!!!!!!!!!!!!!!!!!!!
All that was necessary was to keep the delivery in straight line, and the boiler would have been very happy.
KISS! Or KISS,Ahole. If you are reading this bubba, come up and take another look. The last check might be delayed for a while.