I put an ad on craigslist looking for used/NOS GTR parts, or a parts bike. A fellow in Minnestoa responded that he has a used GTR seat. I don't need one, as mine has been fully re-conditioned, so I'm passing along his email in case someone needs a seat:
bsvaith@gofast.am
Photo's also attached. Disclaimer: I'm in no way proffiting from this; just passing along the info.