My contributions would all have some Trek lineage. I have a 1977 TX900 that I think would be on the rare side of uncommon and a 1981 Trek 957 that would be uncommon. The one bike that seems rare is a 1986 Appel. I haven't seen another for sale and understood he only made a few hundred. Not sure if that is correct. I do regret passing on an early Zunow and an early Tesch that would have both qualified for this thread.