Okay so first of all - I didn't take enough pictures to do a proper tutorial, so I am just going to post what I have, and write up the process so the next person who searches this finds some encouragement. The information is out there for the most part.
I have a 1978 CB750F, the seat was in okay shape, but ugly so I decided to reupholster it.
I purchased the cover from Pit Replica on ebay, 80$ shipped. It came from Thailand, though my tracking information started in Germany. It arrived fairly quickly, faster than I would have expected - less than two weeks. The product itself is decent quality - Well made, but not a perfect match. The vinyl is slightly different - not better or worse, just different.
Tear down: Very straight forward, remove everything that is removable. I used a small screwdriver to remove the rectangular clips on the eight rivets in the chrome strip. I hammered them flat and was able to reuse them no problem. Once you remove the chrome strip the hardware slides out of the strip through a small opening, I threw all the hardware in the ultrasonic cleaner. The passenger strap threads out no problem, however the bolts holding the buckles on were pressed to prevent the removal of the nut. You could easily use a tap/die here to fix the threads, I didnt have the right size so I used a needle file and cleaned out the threads by hand, took 10 minutes, but I was able to reuse the hardware. To remove the actual cover I carefully bent up the spikes around the perimeter - I only bent them far enough to pull the old cover off, I didn't want to overstress the tabs as they had some rust. After that, it slid right off and I was able to clean up the rust and the edges and the foam.
Prep: I just cleaned up the rust around the edges, reaffixing the rubber strip around the edge of the seat pan. I put the new cover in the sun so that it would be nice and stretchy (its in the upper 90s here) This would be the time to paint the seat pan if you were planning on doing that. Also the time to rebuild/replace the foam. Both of mine were fine. I did stretch new plastic over the foam so the cover would slide on better, and to further waterproof the foam. One thing I would I do before you start putting the new cover on is mark on the seat pan where the 7 holes on each side for the trim are. Mark them toward the center so you can still see them once you start recovering the seat
Reassembly: I roughly followed
http://www.diymotorcycleseat.com/modify_4.htm which has been posted here before. One thing I will note - you're not going to be able to use a staple gun on the metal seat pan. You can however pre-drill and rivet, though I did not. I Laid the cover on the seat and stretched the front and rear over one spike on each side. From there I just worked my way up alternating side to side, skipping every other hook on each side. Then I went back and got the ones I had skipped, continuing to alternate. You will most likely have to undo some of the hooks and stretch it further a few times. Finally I did the front and back. I know these instructions sound pretty lame, but it is really that easy. I left it in the sun for a bit before finally re-stretching a few points. Once the cover was on nice and tight I took a small philips head screwdriver and poked it through the 14 holes for the chrome strip, using a slightly larger one I poked the two holes for the strap. Load up all the bolts on the chrome strip and put it back on with the rectangular clips on the four rivets and the three bolts toward the back. I had to grab the tip of bolt with pliers and use an ignition wrench on the six rear bolts so they wouldnt free spin. The passenger strap included is significantly longer than necessary, just measure it out and use a punch to put it all together, then thread in the buckles and use a carriage pin on the inside.
That's pretty much all there is to it. Just hammer the teeth flat and clean up the excess fabric/plastic and go.
I know there is nothing ground-breaking here, or really even any super-helpful details, but If I had read this a year ago, I would have recovered my seat way sooner, it was literally the 80$ for the cover and a couple of enjoyable hours working slowly. No surprises, no special tools, and really no difficulties, I was able to reuse all hardware and the chrome strip. (I realize the chrome strip on the 78 750f is more substantial/integral than on some of the other bikes) There are a lot of other options out there for covers, some cheaper, some more expensive, this is a great solution for a daily rider that wants to look nice and perform - it isnt a 100% stock museum solution.
I hope this helps someone - giving back what I can for the million times I've found help here!
