This 3D Model is to replace "Part A" from the Hardware Section featured in Arcade1Up's instruction manuals. Looking at various instruction manuals including my MVC2 Machine, "Part A" is a Wooden Peg that is used to secure two parts before screwing them together. This part is made to replace the original wooden part in the event that it breaks.

There's a chance this part might be different depending on the machine, but this part matches the measurements I took from the piece included in the Marvel vs Capcom 2 Arcade1Up machine.