Identifying output transformers

I have a couple of excellent output transformers from old broadcast equipment.
The number on them is: ST 4779/1.
They have a very good frequency response: 5 Hz - 50 KHz with low distortion, even at moderate and high levels.
Could it be that they are made by Haufe? The number ST xxxx makes me think this.
Is there any information about them on the Internet? (I couldn't find it...)
Of course I could ask Haufe, I asked them before about other transformers but I never buy anything from them...

ST = probably Haufe. Are they round cans?

the ST toroid i tested were not that great, low end really sucked current, (low henries)

@rafafredd: No, they are not. Traditional E and I core.

@CJ: I agree with you. The Haufe torriods are not as good as the ST 4779/1's I have here.

This is how they look:

looks nice. I think probably not haufes.

On another question with a 600:600 output  , how can you tell which is the primary and the secondary ?
I have a few with 4 leads , tia

If they are 1:1, I don't think there is very much difference between primary and secundary.
But I am not a transformer specialist...

a 1:1 can have maybe slightly better common mode noise rejection if it is used the right way, pins 1-6 on pri etc.

this is because thy can bury the pri coils inside the sec coils which tends to shield the pri a bit.

depends on the xfmr,