To some extent (or other), it depends on which version of the ST .60bb it is. There were "light" and "heavy" which had thin and thick cylinder liners, without or with muffler lugs and some other subtle changes. Bent head fins, oversized mounting bolt holes and such detract quite a bit, at least on eBuy. Pictures would help.

Steve
Edit: Just thought maybe posting pictures would be a problem. If you email them to me at: sbasser at yahoo dot com, I will crunch them and post them for you. Usually about 15-20 sec per picture, using IrfanView.