I think it is the latch. The door is level and has no wiggle...so the hinges are good and tight (bushings look good). The door takes a very strong push to get it to close latched. It closes half latched. Are there some tweaks to make? Ideas from your experience with cars of the age?

 

Have you tried to adjust the striker?

 

I have not. If it can be moved, that would likely solve the problem. I assume then if I loosen the striker it can move a little up/down/forward or back? Thanks for the idea!

 

There is access through the vent .

 

Thanks guys. Adjusting the striker worked perfectly. Door closes smooth now.