In my opinion you were very smart to redo the rear window seal/joint. The first fastback Barracuda I owned rusted out from the leaks around the rear window. When I bought my current FB Cuda I removed the rear window, removed all the trim locks/pins (they collect moisture), prepped and undercoated all the seal surfaces and had the glass man re-install the glass with urethane. It wasn't that simple but the glass man had numerous rolls of different shapes of rubber trim which we fitted around the opening until we got the correct fit. Of course I had to sell my old window stainless ( $350) because it could no longer be installed but now there's absolutely no place/space for water to collect and no place for rust to even begin!!
I did the same with the front windshield, no more leaks and no rust (EVER)!!
PS - GREAT WORK!!!!!!!!!!!!!!!
treblig