This design was patented in 1913 by William Finney. According to Waits it was manufactured by the Supreme Razor co, Unionville, CT. and was the predessor to the Superman (See HERE). It must have been one of the first Gap adjustable safety razors.
It uses King of Cutter blades but I made a new back piece for a Gem and it works perfectly. The gap goes from Zero to just under 4mm - so its HUGE.

The whole top is basically two pieces of flat spring steel which have been shaped and riveted together, nothing much to it at all. It dismantles into three pieces but operates as a one piece. The blade just slides in and is tightly held in by friction.
The top cap is more elaborately engraved and adjuster knob is slightly different and there are no markings to indicate "Gap".