Cabinet Heater, Space Conditioning, Inc. Model WD10-TF

This hydronic cabinet heater was manufactured in Harrisonburg, VA. and installed in the mid 60's. It has coil, blower motor and what I believe is an integral circulating pump. The blower motor has a female "drive" I believe that fits around a mating male snout on, again, what I believe is a circulator. One clue, there's a leak behind a cover plate. What is more interesting is the female drive has I'm sure a magnet insert that fits around the male snout when the motor is installed. The male snout does not spin so could the magnet spin an internal impeller. I'm using "I'm sure" often because that's what I believe is happening behind the scenes but I don't want to direct any thought. The circuit is not well isolated although I started to remove the cover plate I figured I could easily turn a small leak into a big one. I'd like to save it if possible. Is there any info, manual or parts out there. It heats a basement where the boiler is located and pipped from below the heater. No air scoop, few valves, no flow checks. Any assistance is greatly appreciated. Jeff C.