Ask and you shall recieve! (Flip Top Gas cap Adapter)

This pic caught my attention.. I need a little clarification, as my adapter fit perfect.. What I noticed is your filler neck appears to mount on the outside of the quarter.. (like the slid it in from the outside and bolted it down... On my 69 Dart it was exactly the opposite.. the filler neck was mounted to the inside of the quarter. only the heads of the screws were on the outside of the quarter... did Ma Mopar do it 2 different ways?? Or was mine a fluke? Anyone else have any insight on this?

All 73 ups were mounted like this...
Also Dart Sports and Dusters only have 3 screws holding the filler neck on
While
Dart and Valiant 4 doors as well as 2 doors have 4 holes to hold the filler neck on

I'm actually '75....same on '74 ?
That is how 73 up was mounted...Refer to upper part of post to see other differences^^^