Thanks for posting this. Interesting about these screws. I found the 2" ones in your kit were too short only engaged by a few threads I opted to replace these with 2 1/2" 5/16 -18 Stainless steel socket head cap screws with Aircraft AN 916-5 washers.
I know this violates originality but these can be changed at any time. I used SS socket head screws for all parts of the build because I like them and I have no plan on selling it.
Had I known about the pocketing I probably would have done that
I also had a question about the face plate screws. I found the ones in the kit would not fit. So I measured the originals?? which I only had 2 of, they were a slotted pan head screw with an 8-36 thread which is a very rare thread size. I could only find this thread from McMaster Carr as a button head. Your kit came with 8-32 screws and I was wondering if someone jammed in 8-36 screws effectively re-threading them or did some units at one time come with 8-36 threads.