Unknown micrometer

[Toolmaker51]

Marv and metric_taper have good justifications, especially what position the spindle tip is from the radius at zero. My question is the tip itself, is it flat (conventional), reduced diameter, or pointed?
Another detail about the clamp-screws; appear to allow zero anywhere. That makes possibility recording difference (instead direct measurement), compared to a standard; or vice-versa of course.
No doubt micrometer head is Shardlow, but foot was generated as specific tooling, in manner described post 4 by clavius. If was commercial, high likelihood to be finished satin chrome as the thimble and body.

Next page post 13 Tonyg reports
"Hi ,
The tip is flat and it does allow it to zero anywhere."

Quite conclusive factor there; it's a comparative instrument, not absolute. Could set any kind of plunger etc, if maintaining linear axis to it.