A search of the net shows only one relevant post re: CCKW issued jacks. Its on CCKW.org (you can google it).
Seeing that I have yet to uncover a real jack, I have started to search for an acceptable substitute in form and function.
So far I have uncovered the following:
Simplex model HJ3:
And Zinko model ZN-12:
While not exact duplicates, the fact that the pump mechanism is in the front of the cylinder seems to be a somewhat unusual configuration.
After a coat of OD I think that they should be at least similar to the CCKW jacks that all seem to have been thrown away.
Has anyone uncovered a crate of CCKW jacks that they want to post pics of or sell? I'm in for one!