[highlandlake]

Hi there Hogie,
You can use the seat from a 68 and a 69, same body style. (not a convertible- has a different width) Check around first, but a same year Cutlass, Skylark, Lemans, Beaumont may also fit. From my best recollection 70 to 72 A-body cars may have had a different width rear seat but I could be wrong. A reputable and knowledgable old-timer junk yard guy may know for certain.
For what it's worth they aren't really difficult to re-upholster yourself if that is all you need done to your current one or a junkyard one. Go to Paddock.com or Year-One and buy the pre-made covers. The two-piece rear seat is easier to re-do than front buckets. A pair of hog-ring pliers, an able bodied helper for the final stretching stages, some patience and no beer beforehand is all you need. Hope this helps.
Tom