As I'll be painting the ignition leads on my S.E.5a soon, and not knowing what the proper colour would be, I'm just wondering what kind of insulating material was originally used on WWI aero engines. Was it rubber or a woven material of some kind? If they were covered in rubber, black would be a safe bet I would think, but if a woven material was used, they could be any colour. It seems to me that a restored engine would use modern leads so their colour might be suspect.
Cheers,
Chris