Are you recreating a factory 76/77 GS125? Why did you cut the steering head to fit the Hercules/Ceriani forks?
P.S. Looking good!
Remember this will not be a recreation of the standard 72/73 Zuendapp for the museum.I build MY special ISDT replica Zunny in the mid 70s ,wich was a great bike,and now I try to recreate that one out of my memory.
One of my mods at the time was to install a 35 mm Ceriani Hercules fork matching in length the longer rear shocks anf get away from the thinner and very flexible Zuendapp fork.
Basically I followed my ideas of what would work better on the Zunny,just like I build before in 1970-71 the White OSSA 250 ISDT bike.
I never left any of my bikes in standard condition,not even my modern days KTMs.
I know that the factories could not do all the mods on the marketing bikes because the retail price would be out of the World,and so the BETTER mods where only done to the real factory bikes,a handfull only.