Thanks to the amazing people on this forum, I was able to redo the seats in my 40. Thanks to all you who've detailed your journeys; I patched info together from all of you and I thought I'd walk you through mine, start to finish.
First off, I bought coral seat covers from @Cruiser Corps and they're terrific. I also bought the foam and hardware from Specter, which worked great. I know others here have described making their own foam; I'm sure that works but both these purchases got me ahead of the game.
Here's the list of stuff from SOR.
I want to say the whole thing was around $1,300-400. NOTE: Before the project, I had one angled 72-73 bench seat and one squared earlier one. Thanks to Jeremiah I was able to pair up the angled ones (I'm tall so my driver's seat needs some clearance behind it) and go with those. The foam and covers are PERFECT.
Here's the before:
Non-original recover at some point. Super clapped-out as my friend liked to say. I had an OME 2" lift put on a couple years ago and was dismayed at how crappy the ride was; with the fixed seats it's way better.
I pulled the rear seats out, sanded and painted the frames with the Rustoleum Satin Nickel spray paint. Perfect product imo. I had a few spots of rust in the crevices, so I hit those with rust converter. Then sprayed 3 or so coats of paint.
The foam and covers were prestty straightforward on these- like everyone says, get the covers hot in the sun and they should be easy enough to work with. Don't forget the new straps and twistlocks.
Then I turned to the passenger seat, which had a huge tear in the back forever.
I'm guessing, by the headrest anchors in this shot, this seat wasn't original to this '70. But I could be wrong.
Turns out at least one critter got in through the rip in the backrest...but never got out.
I cleaned and rust converted this and it cleaned up nice. All springs were intact, too, which was a bonus.
Here's one of the "a-ha" moments I had when searching other threads- I meant to tag the user who came up with this but anyway, roll up foam and stuff it into the springs for added stiffness! Genius.
Then, following advice found here, I bought bulk floormat material from Ace and cut it and ziptied it to create a barrier between the springs and the foam. Again, genius.
I did order a bunch of hog rings from SOR, but after the first one I said F it and bought a bunch of zip ties. A hell of a lot easier for me, and I'd say why not. Note the zip ties here:
Then I screwed the freshly-painted back panel on:
I put all my body weight onto the spring/foam/cover package and ziptied real tight. Then I followed up with the screws and panels, and it worked great. Just smush the hell out of the thing.
It was now time to address the most important seat- mine. What a POS. I hadn't realized that the PO (which is most of the term "POS") added a DINING ROOM CUSHION to his redo years ago. Just wow. No wonder my spine came out my mouth on every bump...
Again, fortunately all springs were intact, so I sanded, sprayed and put the foam in like before.
Here's another tip: After ziptying real tight, I poked holes in the cover where the screws go so I could find them with the driver. I'd leave the awl in there until I was ready to screw.
Driver's seat also had a plastic headrest base, I'm guessing. Weird.
I did use wire around the edges of the covers, and had to poke the wire through in places. It was a little secondary to the zip ties and screws, but I think helpful overall to give the screws something to anchor against. The wire was a bit time consuming but essential, I think.
The driver's seat assembly is a PITA; be very careful taking it apart and putting it back together. Take pics and follow them- note the plastic piece in this first pic; without this, the clearances would get messed up with the seat slider etc. Also, the springs on the bottom have to go just so...trust me, take lots of pics. It's easy to put something on wrong.
I finally had all seats ready to reinstall into the empty 40.
I can't tell you how happy I am with the upgrade- not only the looks but they're so damn comfortable. It took me 3 years to get to it, wish I had done it sooner. I think it took me around 25 hours, and about $1,500. If you're on the fence, go for it! If I can do it, you definitely can.