Finally some progress.
Firstly specimen A, as sold here:
https://www.aliexpress.com/item/Tran...712131800.html
Test equipment:
1. calibrated Keysight U1241C DMM
2. calibrated Fluke 62Max IR thermometer.
3. Loads consisting of a selection of wirewound resistors connected to a choc block
Unloaded voltage on the LV winding is 7.4V RMS
Loaded voltage on the LV winding pulling 600mA (60% rating approx) is 6.3V RMS on the dot.
Unloaded voltage on the HV winding is 162V RMS.
Loaded voltage on the HV winding pulling 17mA (85% rating approx) is 146V RMS
Left for two hours under load, the temperature of the transformer windings measured with the IR thermometer peaked at 41.6 degrees C. Chassis at 38.1 degrees C.
No sign of any problems, degradation or breakdown.
Next one coming up in a few days ...