There is a list of spares and discussion on pages 4 and 5 here
http://www.talkmorgan.com/ubbthreads.php/topics/541638/4.Sources of spares:
Matts Machine shop for S&S engine parts
The fuel pump can sourced from Land Rover specialists
And the alternative rectifier is a Harley Unit
See this list of alternative spares compiled by Planenut:
https://www.dropbox.com/s/gbrfaonbh9xqwan/Updated%20list%20250119.pdf?dl=0