[Milsurplus] Teletype Corp. REC10 power supply?

[Hue Miller]

I have this unit, heavy, black wrinkle finish, which i assume is loop supply for
 TTY machines. I see by the schematic it's apparently a resonant regulated
type transformer. Is there any practical use for this xfmr, like for an isolation
transformer? I do not know its specs. Or, should i just use it for what i bought
it for so many years ago, which is, as a housing for a homebuilt power supply
for other black wrinkle eqpt?
tnx
-Hue