Doug,
I looked on the internet and in some of the specialty catalogs and could not find the specific tool you are looking for. I typed in " determine wheel offset" on the msn search page and there were over 15,000 hits. I looked at some of the first 2 pages and there are some good detailed explanations on how to determine offset or backspacing without spending a bunch of money on a one time use tool using things like a straight edge and ruler. Try looking at them and see if they will answer your question.
Good luck,
Gary #06984
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