After a lot of fiddling around, I'm happy now with the sit of the passenger side braces. They now line up with the drip rail and drip rail trim and inner door trim pieces. Also replaced the lower rusted out section of the rear vertical brace.
Starting to make better use of the Cleco metal fixing pins. Not surprisingly, finding that if I drill the Cleco locations before I drill out the spot welds to take a piece off, they go back in the 100% correct spot each time while I'm creating the rust repair sections. I guess better late than never ...
Now that I have both sides braces repaired, I've started re-fitting the rear end pieces - "dry-fitting" at this stage to get the alignment all sorted out. I've spent quite a bit of time trying to get the passenger side wheel tubs in the right position.
Again a lot of fiddling, but using the Clecos to keep the reference point the same should make it go a lot quicker and closer to how it should be. The inner tub on both sides is the original tub - so I used the drilled out spot weld holes as the initial reference to get the inner tub lined up as close as possible to where it originally sat. I've then matched the sometime replaced outer tub to the inner, then Cleco'ed in place.
I've got a few rust repairs to do on both the inner and outer tubs before I'm happy to move onto the drivers side wheel tub.
As I got this far, I just couldn't resist clamping on some of the new metal pieces to make me feel like there's some real progress happening

New pieces in the pic below - parcel shelf, trunk floor, right hand side trunk drop side and deck filler.