Waddell...Trevor Bayliss... that's almost pre internet!
I would try the sail on a 430 mast first.
Remember, the top will not "twist off" on a sail that old.
The did not design them to be floppy on the top.
Best you can do is to get a 430 mast and downhaul unitl
the battens pull back to about the back of the mast, and
the luff sleeve become fully tensioned around the front.
Are you sure there are no specs on the sail bag?
Hope this helps,