It is a "minimum system" scope, w/ the classic "octopus" circuit built-in, and it is factory made. I don't know if they used it internally only or it was a public offering. The octopus is a short form, minimalist, simple curve tracer. But it is incredibly effective for Q & D bench work. All you need is a filament transformer, 3 resistors IIRC and a scope set for X-Y mode. The Navy OS-8 scope has the same built-in w/ jacks on the panel for such testing diodes, transistors and junctions.
|ET-4382 Diode Test Set|
|Testing a Diode|