If it was me, I'd look on e bay for a micrometer head unit without frame, I see them fairly often, perhaps cheaper than MSC. A regular micrometer does not make the best lathe stop, the threads (40TPI) are easily damaged by excessive end thrust; you might consider making a similar stop with 20 TPI, like 1/2"-20. I have a commercially made one off a Monarch tool room lathe that I adapted for my 19" Regal Leblond, it looks like a common micrometer, but with a larger barrel.