Looks like MOTS? I have one exactly like that except it has a cream heat-shrink covering instead of MOTS. Mine's probably late '50s-1960. Note that the magnets are the vertical blocks that the screws go through... and you can install one backwards and kill your output, make sure that they are both N up or S up. I tried some replacement magnets and they didn't change a thing, the old magnets were still good it seems. Best part was the 5x7 baby tube amp that came with it... 12AX7, 6V6, and 5Y3, classic. Put a pedal and the rig screams!