Yes, you can get the covers from the various catalog companies such as LMC. My 1969 truck is a CST/10 and the original seat covers were brown vinyl with the scroll and pleat patterns shown in the LMC catalog.
Old:
http://67-72chevytrucks.com/vboard/s...d.php?t=731496
LMC:
http://www.lmctruck.com/icatalog/CB/full.aspx?Page=87