Hi Keto:
Those appear to be DS-050\600 which is a rare bird. It has a 5,000 ohm single ended airgapped
primary winding with 600, 337.5 and 150 ohm secondary taps. It could be used as both a linestage
(i.e., preamp) output or as a earphone\headphone output trans. Obviously it power handling capacity
would be far in excess of what you'd ever want to shove into your ears :=)
I believe that I may have some coil stock left for these guys.