I was a passenger in a Mercedes SLK 230 recently. I thought the seats might make for good transplants for the Pantera. They are thin, narrow, sturdy, well padded, trimmed in leather, they have side bolsters, and they have adjustable head rests.
The mounting base may be a little high, hard to tell unless you try fitting one in the Pantera. I don't know how easily they separate from the Mercedes mounting base either, as its hidden behind decorative plastic.
Food for thought however.