A few years back I acquired frame 28 and it came with the original hand made master cylinder cap. At the time I also owned frame 248 which also had one of these hand made caps but it was damaged. So I decided to see if these could be reproduced to original. There is much speculation as to what frame numbers came with these caps fitted but, I can say that my frame 248 had one of these caps. I heard the first 10 bikes only had these caps but frame 28 and frame 248 has put paid to that theory. What bikes had them I'm not able to say but my guess is they were fitted to at least the first hundred and probably sprinkle fitted to anything after that.
Anyway, after much searching I found an anal machinist whose mission for that year was to replicate this cap, and after a fair amount of time and cash I ended up with a dozen or so billet caps. I've sold probably over half of these to members and friends and have a few left for sale. This lot was made by hand and if I recall cost me around $200 per cap no allowance for anodising
Pictured is an original cap, a cast cap as well as the final billet caps. The picture shows these without anodise but I've had them all anodised. I was intending to keep what I have left and really don't know why, maybe my hoarding nature I guess. Anyway, if anyone is interested I've decided part with the remainder of those I have. Remember these are all hand made (CNC machines were not available in 1969), so come with machining marks for free.
If you are interested let me know but they're not cheap KP