suddenly stopped working, although the speedo is still ok, so I'm guessing the little geared wheel has broken or jammed someway... happened before, about 4 years ago, and I was able to find a replacement speedometer head in the local junkyard. At that time, I noticed there were several different configurations, but got lucky. I was wondering if I don't see exactly the same type, can I likely use the gear out of a slightly different model? That is, did they all use pretty much the same guts, just wrapped in a different cosmetic package???...