If the CRT has an intact heater & shiny silver getter, it is probably fine. Lack of EHT is more likely to be a problem, especially if there are leaky paper based capacitors in the EHT circuit, or a bad step up transformer.
Also there are several 5AQP type CRTs on ebay, two which look to have been pulled from old oscilloscopes and one very expensive NOS.
David
factory