The brass wheel in the middle of the plane is used to adjust the blade depth. This is a later model.
This is likely one of the last Seigley-type plow planes made. Stanley bought out Seigley & this plane actually has several thumbscrews from a #45. The tongue and sash cutter depth stops are also exactly from a #45. It also has a 2-piece beading stop very similar to a Stanley #55 beading stop. Alot of similar planes were sold as Union comination planes.