Not Zzyzx - they weren't upside-down forks.
the Hanebrinks that the Zzyzx's were based on were USD but they were a lot simpler in the crowns and didn't have a steering stop.
Foes is a good guess because of the steering stop, but F1s and XTDs all used a 30mm axle. The Big 'Un only went up to 20.
I've had Zzyzx (stiff but crap), Hanebrinks (stiff and not quite so crap) and currently have lots of F1s (awesome in all ways) so I can recognize all of those features.
I don't recognise this at all - Stratos or Risse would be my guess.