Hi Gene,

It's a 513-401 -- it has a 6mm stem, which doesn't pivot. If it did I think I could just mount the indicator in my collet. (I could do that for finding the centre of a hole)

It also has dovetails, so I've ordered one of these: Dovetail Indicator Clamp Holder NEW | eBay -- I think I may have to cut it down as I'm short of Z height.

I'm certainly learning a lot -- I only just figured out that you can change the angle of the test indicator contact point!

Tom