Mystery Peerless Tranformer

I have an old Peerless/Altec transformer with part of the label missing. The part that is there states it is a Type B-1... Unfortunately the rest of the part number is missing. I've looked through their catalogues from the era I believe it is from (50's) and there is no 'B' prefix letter id to be found.



Any ideas?


I'll try to take some photos in the next few days...