I’ve just had a close look at a Type 1, the holes down the middle of the two ‘tubes’ have a machined finish. What if Ed Stevens was correct and the forging was then bored out?
Vince Farrell
Mine shows the machining in both tubes also, though I would have expected it in the bearing housing tube. If you look just to the rear and down a bit from where the serial number is stamped, at least on my Type 1 headstock, there is some type of symbol that resembles the foundry or forging mark found on some other parts like footpieces, footrest brackets and other non-tube parts scattered over the motorcycle. I can't say what the symbol means, but I am sure someone knows and it would answer this question.
Goodness, why are a dozen or so of us all over the world up doing this on Christmas? Hope you all have, (had), a great one. I'm looking forward to cooking a wonderful big bloody beef roast in the ESSE woodstove today with one of our best wines from down cellar.
Ron