I have also heard of a conversion kit, but it was long ago when they stopped selling 3 wheelers. Not sure how good they were, and bet it wouldn't be cheap or easy to make it work right. Only 200 miles? Thats amazing, and I bet you could sell that thing for a decent price if you decided to in order to buy a 4 wheeler. Those sure were popular back in their day and I still see a few in the beds of pickup trucks these days.
markc :-)