upholstery grade vinyl is pretty readily available.... heat gun on low is what ya want.. good 3M spray glue... sponge and bondo spreader work well for smoothing out.... denature the heck out of it, scuff it, denatured, spray glue, go to town...
my Chevelle one was similar in difficulty to a K5 I'm thinking... couple tricky spots, but heat and patience can get it done... the big mistake most make is bad prep and rushing the glue... make sure you treat it like any other contact cement job, coat both surfaces... the drier the glue the better...
mine came out pretty much perfect and it ran me probably $30 and a few hrs labor...