Great thread, I’ve got a lot of the same repairs on my 69 panel van, it’s windowed but I’m going to return it to a panel van, same issues with rear corners on mine as well.
http://forum.earlybay.com/viewtopic.php?f=2&t=74708
Sorry about your loss, lost my dad on 2009 and it was same situation, he taught me everything I know and he was a mechanic, miss being able to phone him for advise.