I may be wrong because the market has been changing but I don't think there is much collectors value in a CT. There were sold extensively in the US and there are still a lot left hanging out in barns and garages. I don't see any reason to save the original motor to reinstall at the point of sale. Some folks do like to keep them stock but modifying them shouldn't effect the value unless it is done poorly.

Doug - Olympia - Washington
 I don't know how many CTs I have.