Yeah, I agree that it looks kinda like a PortaColor, and the basic styling might have been inspired by the PortaColor, but it sure ain't a PortaColor.
The basic front-panel confirguration is PortaColor-ish, but the main cabinet looks a lot more rounded-off than a PortaColor, and the recessed hinged plastic handle is definitely not PortaColor-ish.
By the way, Andy, other picture tube designations used in PortaColors include the 11SP22, 10VABP22, and 10VADP22; there may be others. [Also remember that "11"-inch tubes became "10" after the FCC changed the rules for advertised dimensions of picture tubes.]