Hi Paul,
I have a copy of an original J.W. Automotive parts manual. Dimensions are given for nuts/bolts etc only, but the line drawings of all parts, including the uprights, are superb. Happy to share these with you if you think they would be of any use. I believe David Brown at Classic Car Developments here in New Zealand (Ph/Fax 64 3 215 6893) may have original factory drawings of the uprights.
Cheers, Brian.
[ October 24, 2001: Message edited by: Brian Stewart ]