Fixing water leaks into trunk on '70 Duster

I found out a couple months back that water is leaking into the trunk of my 1970 Duster. Unfortunately it must have been happening for a good few years because I had (stupidly) taped down some cheap roll-up insulation in an attempt to reduce noise probably 8-10 years ago but it didn't work; upon removing the stuff a couple months ago I saw that what used to be a pristine trunk floor pan now has surface rust from water pooling and collecting under the insulation, I feel pretty dumb now :mad: lol. Shouldn't take more than a good sanding/wire wheeling and some rust converter to get it to stop.

Anyway I did some tests and it looks like the water is leaking in from around the bottom corners of the back glass; I removed the trim around that area and there is a bit of rust but it looks minor enough to hopefully repair without having to remove the glass. I think it's also leaking in through the screws that hold the glass trim on. Basically if I pour water over the rear window it starts dripping slowly from a gap in the inside steel panels near the trunk lid hinges.

Not to mention water leaking in from around the taillights but that seems straightforward enough to fix.

I'll post some pics after I get home from work so it's easier to see what's going on.