inner fenderwell or quarter first?
 

Im replacing both of these, since the inner braces the quarter panel im not sure if I should tack weld the outer patch in first then snugly fit the inner fenderwell up against the quarter then tack it in also then weld it all up? Seems to me that would be the best way.. ? any trick to doing this?

always good to have them both in loose, mark where the wheel house is sitting so when you take off the quarter you can do some welding without the quarter in the way and in the right place. Just make sure your quarter is where you want it. cleckos or self tappers are good to hold your pieces up.