George:
I think i found the tool. I'm having trouble with this website, can't get everything to load:
http://www.********.com/sirtools/tools_benz.html
Go there, I think what you need is M 0025, $65, which if it's correct seems like a deal to me. Plus you'll need a metric dial indicator, probbaly with a 2" extension or so. (or a fractional inch dial idicator if you want to do the conversions)
Gilly