On Stunthanger, john e. holliday has a recent thread on J.Roberts Sabre and Cobra. He has the kits and has been tracing the parts on paper.
http://stunthanger.com/smf/index.php?topic=20212.0
Looks like J.Roberts stuff is pretty well known to the "old" guys...
I think you need to register to view that part of the forums. Which is not a bad idea anyway if you are into C/L.
I think this thread on Stuka Stunt might have something interesting:
http://www.clstunt.com/htdocs/dc/dcb...ng_type=search