
The quarter panel flange was left solid so when it was clamped together we could weld to the flange through the inner quarter panel (below the 3 holes):

We used a variety of vice grips through the 3 holes in the inner fender and were able to get everything nice and tight on the flange. It turned out great, with a nice and tight seam. It will get a little seam sealer when the car goes to paint and it should be good to go:

RX-7 GSL-SE Rear End
Motor Mount Jig Rental
My Classic Car