[horsa]

Took awhile to research the code in the parts manual for the drain plugs. But they come from the Ford T-17 Deerhound which was an armored car that was in the running for U.S. government contracts during the war. Guess the Greyhound was the winner since it received an "M" number (M8) with the T-17-E1 Staghound a close second since they were also produced in limited numbers. The T-18-E2 Boarhound was another in that contest.

I've not found a source for good replacement drain plugs and nothing modern has the same dimensions. A machinist friend that has a T-16 milled plugs for my vehicle which are installed in the rear section where they wouldn't be visible but can be removed from underneath if needed. He patterned them with large hex heads that are the same size as the hub nuts in the rear end. That way the same large socket tool would work for them since it would already be part of the tool set carried on the vehicle.

These are a good alternative but would only work on vehicles that still have useable threaded flanges on them.