I'm trying to get some brackets fitted to my Crabb C/G Anglo, No 14052, made about 1958, and to do this Jake (Wolverton concertinas) needs fit 2 slightly longer end bolts each end. They are not BA or metric thread, and Jake can't work out what thread design / size they are. If we knew he could replicate the bolts on his lathe, with a new die to cut the thread.
I've emailed Geoffrey Crabb, but as yet haven't had a reply - it may be that the email address I've been given isn't now looked at by Geoff.
If he sees this perhaps he could contact me - I'm happy to go to Bishops Stortford with the machine if that helps.