Thanks Jakoba. 01/78 so far the earliest.
Grumpol, yours is what is common since 1969 (parallel to starter).
MrZxp, got a frame with a manufacture date for that F motor.
I need more. Earlier to Jakoba, or later that year to see if they remain that way, or any with parallel with later dates.
One thing to note is the bike history should be known.