CRT needed for Panasonic Orbitel

Filament's open. Sticker on chassis calls for replacement "150ACB4". Offhand, anyone know of some same-size b/w CRT's from some of the other portable sets that will interchange? I've got an old NOS Sony 6H-50 but the anode connection is different. I don't find the generic replacement # for this tube listed in any of my Sams and these predate this set by a couple of years, so any help here is appreciated!
Thanks,
Michael