You can see that the Bluemel boss (bottom) has the retaining bolts closer to the outer circumference than the Ashby boss (top). Your broken one looks to have the spacing of the Ashby one. Much harder to find!
my f2 had an ashby wheel but it was a bit rough so I fitted a Blumells wheel and it fitted straight on although the top did eventually break like that one but it was not difficult to make a new one
I have welded these up and tried to follow the correct procedures / use of filler metal but would only trust a welded mystery alloy part for display purposes.
quote:Originally posted by Nick Dean
Bob, why not get the boss welded up and then machine/mill out correct grooves. Looks a fairly ordinary welding job. good luck, Nick.