To update this thread, I've given up on the 5153's antique and inefficient power supply. Even though I got it to work on 230VAC, it runs warmer than I'm comfortable with.
Standard industrial power supplies are nearly impossible to find with a suitable output voltage and power rating but some came up on eBay
a few weeks ago. There are seven left if anyone else is contemplating this moderately-difficult upgrade. The unit is of adequate quality, the price is right, the output is clean and stable and can be easily adjusted from the specified nominal 110VDC up to the ideal 115VDC. It's rated at 100W and the 5153 needs roughly 60W. It has an internal switch for 100-120/200-240 VAC input.
Aside from implementing mounting and wiring, the original degauss circuit (just one component, a PTC resistor) needs to be cut from a corner of the old PCB and mounted somewhere where it can dissipate heat (first pic at the top.) Also a main fuse should be added just after the monitor's power input.
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