Does this count?
It's a Leica Apo-Televid 77 Spotting scope, SLR Adaptor, T-Mount to Fuji X Adaptor and an X-T1. The telescopes were made for a while and were quite popular, but the adaptors are extremely rare, it took me years to find one!
It creates an F10 800mm lens, depth of field is tiny but it shows promise, you can see a test shot on Flickr here https://flic.kr/p/tgKeZb