[Boatanchors] Transformer ID Help

[Wilson]

I have a nice looking xfmr of typical Thordarson/Stancor type, all black, with smooth end bells.
The tapping and colors are “odd” and I can’t guess its application.
There is a rubber stamped number on the bottom, P-74739-1, but no numbers punched into the metal.
I’ve searched my sources, with no luck.
Does anyone have a catalog showing this number?
Thanks,
Wilson
W4BOH