Mine was done by
Nate's Custom Sewing, and here is a link to the first of several photo's of my seat, which he photographed for his gallery:
Slag's Re-done 1979 Seat.
Here are the photo's from when I sold the bike, showing the seat installed, after a couple of years of being ridden -- still like new:
sale photo's Slag's 1979 K.
I drove up to his shop with the seat in the trunk of my car, but I believe he deals with customers through shipment deliveries, as well.
I went with
marine-grade vinyl: tough as nails, UV-resistant, much heavier than most grades of vinyl. I also selected the red piping, and I discussed with him the color of stitching, as well as the pattern and style. I asked him to upgrade the padding, into a King/Queen seat, however that lost a bit in the translation -- not quite what we wanted, but it wasn't bad.
If you don't want to mess with it remotely, as there are many options, I would highly recommend a local upholstery shop, where you can talk in person, touch and feel the vinyls for quality, as well as discuss the details you want included (foam build-up's; stitching colors and patterns, piping, etc.). Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII