Those two caps are for the two bronze bushings that the pusher bar shaft rides in. You can use 3 in 1 oil or some other light oil in them. I lube mine about twice a year, the bushing are so oversized and the shaft rotates so slowly that even without oil, it would be many years before you would see any wear.
As far as the steel goes, it drilled pretty easily on my old Mag, don't think you will need anything special to cut it.
Hope this helps