Hi Clemens,
welcome at Stridaforum - I’m from Vienna, too 
Yours is a MK1 for sure, amazing that you found it here…
from here:
Old stuff about the past generations of Strida
These bikes are this year - at least - 25 years old 
I’m surely the last one who would want to moderate your enthusiasm…but I hope you did know that there are zero chances to get replacement parts for this ancient Strida type?
KInd regards,
Chris