Need 23BPL4 or 23BKP4 CRT for RCA M/N 232C376 B&W TV

I have a 23BLP4 that is in need of refurbishment. It presently is operational in my 1961 RCA Vista vintage model 232C376 B&W television danish modern console with solid state amplifier remote control. It is showing the signs of needing refurbishment in that the picture goes negative in bright, high contrast areas; the phosphor appears to be good and there are no burns.

Does anyone have a lead where I might obtain one or have this one rebuilt?

Any leads would be appreciated.
Thanks

hwearsch