Replacement oil cap for New Departure Model D Hub?

[justride]

So, like many of us, I have a New Departure Model D, and the oil cap it long gone. Has anyone either a) located a supply of these little buggers so I can complete rebuilding a vintage hub or b) come up with a novel idea for replacing these caps with something else so I can complete rebuilding a vintage hub.

My newly cleaned hub and spokes will thank you for your help...

 

[DJ Bill]

Dang it, I was just in the big box hardware store the other day, and that was on my list of things to look for. I gotta start writing down these things when I remember. I was hoping to find a rubber or plastic cap in one of those boxes of weird hardware they all seem to have.

I'll be watching to see what other guys come up with..

 

[deorman]

Auto parts vacuum plug.

 

[Schwinnspastic]

I have a box full of "D" hubs I'll see if I can get a cap out or maybe just hook you up with a shell, my problem with these hubs is finding good drive side outer cones.

 

[ozzmonaut]

What about all of those English bikes with oil caps? Are they the same at all? I'd say vacuum plug as well.