These voltages found on transistors on the HV PCB of a working monitor. Voltages taken on a 19 inch monitor running Asteroids in attract mode. Meter used was a Fluke 8010. AC input 116 VAC.
I would expect normally operating monitors to show variations as much as 10 to 15 percent; the key is the ratios of voltages and being sure that the B-E differences in the transistors are correct.
DC readings on Q903 are undoubtedly skewed by the relatively high frequency of operation of this transistor and will vary from meter to meter.