ORIGINAL: lildiesel
FWIW, Wen Mac Mk. IIs I've seen look a lot rougher than the one a number of posts above. I think it's been lovingly smoothed and polished. Nice tank, too.
The Testors .049 from the late 70s has a very similar look and a nicer finish, so it would be a suitable substitute. It has an encapsulated spring starter that might be easier to work with than the pull cord on the spinner nut. The McCoy Redhead is the same engine with a stylish red anodized glow head.
My WenMac Mk-II has a shiney finish also.
I believe that Wen Mac invented that spring starter and Testors/McCoy bought the design from them. Perhaps this is the Testors .049 you are talking about. That starter also appeared on the Testors 8000, their last effort.