Wasn't there also a no-name copy made? I seem to remember Enid Puceflange picked one up, although it was bit small for him. May also have struggled with replacing the crumbly elastomers on the back too.
Mark AKA Jimi Hendrix had one for a bit, beautiful looking but a bit fragile. Enid never got on with his, didn't do his back any good. I think Marin made a version.
I don't think it's a Manitou, you're right Marin did make the FRS in Team, Nail Trail & Pine mountain versions I think, could also be another brand called Balance.
I'll see if I can go have a look at it.
They seem bouncy. Both of them
I got the bike to nick a few parts from & sell the rest on, but looking at it it's quite a feat of engineering, tempted to keep the frame :facepalm: