I have to admit, I'm curious again here if this is an MMC3/5 conversion, or if Brian built a VRC4 mapper for the game. I also have to ask: Are those grey cases new
parts? He has the moulds, so he could have made grey cases anew, or he could dye clear cases to grey (as I have done), but they could be old parts, which is generally against the RetroUSB policy, so I'm pretty stumped.
I suppose I'll be adding this to my list of things to order for inspection.