My Louis Marx train set gallery including set 48-21325M from 1967.
The back fo the instruction sheet includes a maintenance guide.
The inside of the sheet shows a number of track plans and the parts required.
The transformer is in excellent condition and shows catalog number 1209, but this model does not appear in the parts order list included with the instructions. Perhaps it was old stock.
Moving the speed control shows the 110-120V AC and 50 Watts rating for the unit. The box side with the output connectors has "7 - 13 V Output" embossed.