need some help with some sheetmetal fitment (pics)

[68RT440]

Hey guys, I posted this in the paint and body section, but figured Id post it here too since I am technically discussing my Charger, lol Ive been doing a bunch of work on the 68' and its time to start hanging quarters. Just to get you up to date, I had the rear end of the car down to nothing. Put in a set of complete rear frame rails from out west, fixed the rear inner and outer sections of the rockers, patched in outer wheel housings, fixed the inner lower wheel housings, put in a new 1 piece AMD trunk floor, a new AMD rear crossmember, and I just welded in AMD trunk floor extensions. Im reusing the original tail light panel, and dutchman panel. The problem that I seem to be having is when I put the quarters into place, the fitment is great, but there is a small gap that im having at the trunk extension to the wheel opening flange. The gap seems to fade a little into the outer wheelhouse as well. My instinct is to slice the wheelhouse and the trunk extension and move the flange over to the quarter flange, but I just wanted to make sure Im not missing any tips or tricks. Oh and its like this on both sides but its a little worse on the passenger side. Thanks for any help:

First two pics show the gap:





And these pics show the quarter in place and how every other place seems to line up: