[FWB]

i'm not familiar with the procomp dist.....but as far as putting a pin into a square hole......it is a practice i have seen in different equipment....the pin only makes contact at the quadrants in the square hole.....and in your case the cap slot also.........but a .125 pin into a .093 hole seems a bit odd.....you sure on your dimensions?. a roll pin will squish down but that far may be problematic.

maybe the pin is metric... 2.5mm perhaps? would make it around .098"