I was just about to post a new thread on DIY seat reupholstery and then I found this thread. So I‘m adding a few tips and pics. Hope the OP doesn’t mind.
First I used a seat kit from World Upholstery for Standard 1977-1985 seat 917 Black Leather Perforated - both front seats for my 1978SC.
First pic is the tools used. This project does not require much tools unlike engine jobs. The only non standard tool may well be the hog ring pliers. These cost less than $20.
After the seats are removed….
The first tip is how to disconnect the wire that the seat release lever uses to disengage the back rest from the seat. You do not need to cut anything for this and reconnecting is also done with the seat fully assembled…just bring the back forward so you can access the wire and clip underneath.
Now use your needle nose pliers to separate the wire from the clip and set the clip aside for reuse.
Once disconnected and the backrest fully separated you can see where the wire comes out a small slice in the back rest leather. You will need to replicate this cut in your new upholstery. The wire is never removed from the backrest. It travels inside the new upholstery down to the seat connector.
The second tip is the backrest reupholstery. The upholstery is attached to the backrest wire frame with three wires in sleeves that get hog ringed in place. The first wire/sleeve is horizontal right below the headrest. The other two run down the sides of the seat back between the side bolsters and the seat back(perforated area). These wires are what pulls the upholstery in tight to the frame and make its shape.
The wires must be salvaged from your old seats as they are not part of new kits.
The best and maybe only way to attach these wires is to completely turn the seat back upholstery inside out and shove it down over the headrest first. With no wires in the sleeves.
Do not have the backrest center cushion installed yet. Install, it after the top wire below the headrest is hog ringed.
Next pic shows the inside-out upholstery, shoved partially down over the head rest and you can see the top wire sleeve with no wire. I’m holding the sleeve.
Now put the wire in the sleeve and lap the ends of the wire over the inside of the seat frame. Note there is no backrest cushion yet.
Now crimp two hog rings on that wire to secure the sleeve and the upholstery to the frame.
At this point you reinstall the back rest cushion and linens and make sure you have the upholstery started very straight and symmetrical on the headrest though the rest of it is still inside out.
Also install the two side wires in the side sleeves. They will be in a big curl up over the headrest. The next pics shows what it looks like when the side wires on in and you are putting back the backrest cushion and prepping to roll the upholstery down.
