Sliding 'patio' door roller hardware

Took this roller assembly off a slider I think dates to the latter 1970's.
Labelled as:
Del Mar Eng.
Long Beach, Cal.
Pat. Pend.
No other markings that I can find.

On a trip to Home Depot I found nearly the identical part--
That protruding tang above the height adjustment that lets the screw that secures the aluminum stile to the bottom rail capture the roller itself. (and hence no door frame disassembly other than the two screws necessary to free the roller hardware)
1 1/2" roller diameter.
All the dimensions and shapes were the exact part EXCEPT:
my part has that lower section. That 1/4" protrusion on the bottom at the guide slot that allows the roller to travel that extra distance and raise the door that amount extra.