Thanks for the advice. If I can fit a glass tube non-destructively and watch the TV while I'm waiting to find the right tube, that would make me happy.
Does anyone happen to have the RCA factory manual? I have the RCA field service manual and an RCA service data supplement, but not the manual itself (Service Data 1955 no. T5). These docs (plus Sams) give me enough info to restore the set, but you never know what handy little tidbit another manual might include. I'd be happy to pay postage & a reasonable fee to borrow one for scanning.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html