chrome fuel door

[mwrbunny]

I just bought one with the "little screws" (I'm beginning to think I got a little screwed!!) BUT in my case, I'm replacing the cheap dealer/factory chrome door set up....because I wanted one that locked. I think the dealer must replace the entire black plastic cup as part of that unit.............so it appears to me that I don't have the stock cup for the new door to grab onto with the little screws.

So, do I need to find a "stock" interior cup unit??