i recall a 19v designation on a late production roundie but dont remember the number.

In the 1973 GE tube manual there is a 19V color tube listed that is 70 degree deflection and has the same base as the usual 21" round tubes. However the screen shape is listed as "rectangular". I think this may be a mistake: I have never seen a 70 degree large neck rectangular tube. This tube may be the 19V round tube you are thinking of. I don't have the book with me so can't remember exact number.

when video display rebuilt my 21 incher they relabled it as a 19"
cant remember the number.