Magazine with stamped initials

I had put numbered labels on my magazines which came with my pre-owned Les Baer wadgun.  I was just replacing the numbers today and noticed the letters RM stamped in the bases of the two Wilson Combat mags.  The lips looked to have been reshaped from a stock WC.  I bought the gun from Larry Carter, but he was selling it from an estate and knew nothing about it.   

Is it just the previous owner’s initials, or has anyone seen a pistolsmith mark magazines?


https://imgur.com/a/olwwLpE