Yesterday, a generous colleague gave me a couple boxes of trains that her family wanted to go away. Knowing that I like trains, of various scales, she had already given me some Lionel stuff, but that another story. In this box, among many other things, was a Union Pacific SW7 switcher manufactured by Revell. I haven't had the chance to see if it works, but it was obvious that it originally had some kind of belt drive. But just as clearly, it no longer had a belt. Since there was no accompanying information, and since I wasn't even aware that Revell made HO trains (in the 50's) until yesterday, I have no idea what that might have been like. So, I'm guessing that someone here has seen one, or even owns one. What kind of belt does it use? If I want to clean this critter up and get it running, what can I use as a replacement? Rubber bands, hair ties? Thanks.