Our lathes are VERY similar. My BXA toolpost mounts the same way with a flaky semi-circular base instead of a proper T-Nut. I've thought about making a better base but it's low on the priorities and may never get done.
But I totally completely and entirely LOVE your indicator mounting post idea! I am forever and always trying to stick something on the toolpost for that usually with a magnet of some sort. The big magnetic blocks suck for that. I saw a Joe Pie video (one of the few I ever watched) and fell in love with the General holder he used. It took me ages to finally find one and it cost me dearly on an ebay auction. But at least I know it was worth what I paid. One of the members on here suggested an Erik and it is similarly awesome - better than the General in many ways. It's the one I use on the tool post now.
However, a million members all voted to get a NOGA two way micro adjustable. But it has the big block base so I don't use it on the tool post - only on the cross-slide or the lathe head.
Your idea just screams at me! I might take a look at whether Noga makes a bar post type with an adjustable nose. That would fit your concept and be amazing. I've just moved the project up near the very top of my priorities list.
THANK YOU
@ducdon !!!!