I have an ex Mil Coventry Climax powered gen set.....240v output.
At a guess it would be WWII vintage.
Its a pretty wee 4 cyl in line, about the same physical size of an Austin 7. magneto zapper. water cooled.

If anyones interested I'll post some images when I get back to kiwiland.
Last 2 days of holidaying in sunny Queensland...weird weather pattern.

Brent.
Wellington. NZ