Good luck with the rebuild!
You can spend many happy hours of research on the net! Here's a link to one of the Gomog pages about the Morgan Moss box and the Jaguar ones,
http://www.gomog.com/allmorgan/mossgearbox.html and if you don't already have them, 'A Yank at Malvern' and Fred Sisson's 'Bedside Reader' are entertaining and very useful for owners of the early plus 4s.
Best wishes
Malcolm
