No I don't Russell. But I do have a sixties era Ford starter motor with the very long shaft. And I might have a rubber boat trailer roller somewhere. Or I could buy one. I was thinking of combining the two. Unlike Simon's bike this would bear against the wide flat outside of the rim, rather than the rim side.
The rim that drives the generator has a 1" section with small grooves in it, as the drive is poly-V belt (automotive type), but the grooves are so small and centered in the wide rim face that I don't think it would bother a wide rubber roller drive.