not a chuffing clue, although I am pretty certain that RF have never made frames before. The adjustable seat mast may well point to something reasonable though as I can't remember seeing such a feature on a BSO
I have always related those with lower end stuff, probably incorrectly. The front triangle looks like a super simple construction, nicely done but almost school project level of simplicity. but there is a lot of detail and work in the rear.
We have at least two things in common ,,,I think it looks great,very industrial,and secondly, I have no idea either,,will keep popping back for updates,,Very interesting.
Mark