There were only under two hundred of those and they were only let out to prospective licensees for examination or for engineering sets.  It is truly the first modern color picture tube. 

It is a variation of the 16" metal shell tubes in the RCA line.  The mask and phosphor assembly was in a separate front piece and aligned in a sort of light tunnel, then welded to the rear bell.  The weld ridge became the anode connection.  RCA went wrong from the beginning.

This tube was use in the tri-color models 1 and 2 and possibly the 2A.  Model 1 was the first RCA demo to the FCC.  These tubes were circa April, 1950 to February, 1952.  Models 3 and 3A used a 3-bolt version.  Starting with the 3, they improved the trajectory of the guide bolts for the shadow mask alignment.  The model 4 appears to be the first of the glass tubes.  Most of what I know can be found in the RCA Color TV submission to the FCC...the "red book"...and in the second "Proceedings of the IRE" on color television.