Hi Graham,
You could try Don Whiteman at Bintel in Sydney (02) 9518 7255
or Roger Davis at Roger's Optics & Restoration also here in Sydney (0425 709 508)
whether it is something they might be able to do for you. Both are telescope
technicians.
Best regards
Gary Kopff
Wildcard Innovations
http://www.wildcard-innovations.com.au