Yep, it's a Ham Std Hydromatic prop blade; you can tell by the blade butt and loose bearing race. A lot of maintenance and overhaul shops put their own labels in place of the prop manufacturers'. I used to work at a prop shop, where, incidentally I overhauled a pair of 23E50s from a DC-3 and re-profiled a set of Privateer blades to fit an Allison V-1710 going into the nose of a Yak-3, and our prop shop had stickers of the HS logo, but it had the name of the prop shop incorporated into the text in the bronze ring around the outside of the logo. They did the same with Hartzell props and the Hartzell logo.
The blades on the Hydromatic props were almost all the same, just profiled differently to suit their particular requirement. Profiling was all done by hand and eye. You drew what you thought was a good outline on one, then traced around it on the others and then cut the tips with a saw and shaped them by sanding until they all looked right.