Hast recht, vespahansi. Habe inzwischen herausgefunden, dass in der zweiten Serie der SS90 die normalen Primavera-Tachos verbaut wurden. SS-Tacho (2. Serie) = Primavera-Tacho 
Für die, die es interessiert:
The truth about 50SS/90SS Speedo's History
In Germany and Italy the first Series of the SS90 had an old Emblem Speedo with 110 km/h scale
the second series (since end of 1968 when Piaggio changed their symbol
had the 120 km/h speedo with the new Emblem)
the first series of the SS 50 had an old Emblem Speedo with 100 km/h scale
and also the second series the 120 km/h speedo with the new one
In Great Britain, New Zealand and Canada both SuperSprint Models had a
mp/h Speedo with the old Emblem and a 70mp/h scale, the last
SuperSprint Models were produced with a 80 mp/h Speedo and the new
Emblem.
But all SS50/90 had a Metal Case and the Chrome ring (so there was no
ET3 Speedo in plastic, or the Rally/Sprint Speedo in black on a
SuperSprint!)
the argument with the metric system is very interesting! But I've seen
at around 20 SS50/90 from New Zealand and all had a mp/h speedo with
the new or the old Emblem....
I've also heard the rumour, that Piaggio exported the last Exchange SS
Frames to New Zealand! So it could be possible, that Piaggio took the
last Speedo parts from GB and Canada for the NZ Model without minding
the metric system of NZ!?!?!
. 
