Although I've put absolutely zero time in to looking for a Formula 1, I think I would regard one as a grail bike, and as such would never expect to own one.
Every memory I have of the brand is with Deb at the controls of one, but it's clear that there must be a few more types and sizes out there somewhere.
Any info on total numbers produced and where they are now?
Photo posted on Facebook by Paul Matthews who kindly let me add it here. Photo from the second round of the 1992 BMBF National Points Series at Clipstone Forest. S1 propped up against the work stand. Clipstone was an XC round only, so assuming S1 was there for display purposes.