Utica Torque Wrench Project; handle seal material?

[Chipm]

I picked up an old Torque Controls Inc (later Utica) 3/8 inch torque wrench. It turns out the ratchet was stripped. Ratchet heads appear to be NLA, so I'm going to try to fab one out of an old ratchet. The handles on these are sealed with some sort of soft metal that appears to have been put in as a liquid. Can anyone help me with reproducing this? Otherwise, I suppose I can always use a hole plug. Thanks!