Interestingly enough, Rob's picture of navy blue matches my seats best. I thought the dark color was black that had faded to green, but it may actually be navy blue.

http://forums.rennlist.com/upload/navyblue1.jpg

http://forums.rennlist.com/upload/brown1_copy1.jpg

http://forums.rennlist.com/upload/black1_copy1.jpg

My only other choice may be to look for a decent used passenger seat or pull my almost perfect driver's seat out, sell it, and recover a set of ragged sports seats I took out of an '82.