Mystery Maker?

During last week’s workshop Make A Set of Roubo Squares (more about that soon) one of the tools I used fairly regularly was this Roubo-esque and very stout exquisite palm-sized square.  I vaguely recall it being in a box lot of stuff I bought at a Donnelly auction several years ago but that could be a false memory.

I have not been able to identify the tool maker but I do not consider myself to be well-versed in that world.  The blade is stamped “Anderson” in script.  It is a fine tool with a lot of heft, sitting in the apron pocket like a brick.

Anyone have an idea?