[NJARC] Unusual UV-204A tube:

[n3ibx]

Greetings,
               Would any of the tube collectors among us be able to identify a glass based UV-204A to a specific application? I just acquired an unusual 204A with a glass base contaning a lip and was curious why it was made that way. Unfortunately, there is no MFD ID, etc.located on the tube, but it appears to have a nickel or tantalum plate which would date it to pre-1935 or so.Any information will be appreciated.
Regards,
            Joe Cro N3IBX