It is very likely, that it was built in 81. I do have the serial number from which on they changed to the new design: 5A8-006759, which was built somewhere before 1982-07-21. So if you assume they built an equal number of bikes per month, your low serial nr. unit was built in 1981, for sure. But maybe someone else can provide you with an exact figure, at which serial nr. the 81 production run ended. I can provide a scan of my austrian registration papers, which show the changeover serial nr., let me know.

Roman
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