I know a guy has a Griefs...as he calls it..
60s enduro.. fliptop gas cap on glass tank I think, maybe Ceriani forks, unit construction motor..
all I can say about it...
I may be wrong on the fork..it may have been a leading link?... like Hercules I once had... they all run together in a blur somedays..... I am thinking, I have probably seen over 100 brands of bikes..