Can anyone tell me what thread Parker uses (particularly on Duofolds) please ?
I seem to recall it is 36 tpi, and measures close enough to that with a thread gauge, but what thread form - UNC, Whitworth ....
Help would be appreciated.
Results of 'experiment' will be posted in due course.

I've also posted this in 'Repairs' - hope it isn't breaking any rules !

Regards,
Ruaidhrí