Steel recess for Le Mans filler cap?

[anguilla1980]

I have a genuine ENOTS Le Mans fuel filler caps that I've been saving just for my current build (69 Firebird).

Before I venture off into my own territory making one from scratch, is this a common enough mod that companies out there sell pre-fabricated steel recesses for welding in in different styles for different size/shape filler caps?

The pic below is similar to the look I'm going for......

Also, how are you guys doing the safety wire on these when you go road racing? I see nothing to keep the lid from vibrating loose of the filler neck and no provisions for safety wire.

Thanks!