Keithley 236 to 237 High Voltage Source Measure Unit Upgrade

PCB photosensitive film:
In this video I am beating around the bush enough to turn 3 simple steps into a 15 min video: 1. Make HV Converter 2. Add transistors 3. Cut jumper link
In my defense, the high voltage DC-DC converter is almost entirely made of standard parts and performs very well. It could be used in many other applications.
Tinkering inside a sensitive instrument like this is questionable but in this case the output stage and precision stuff are neatly separated, so I feel confident enough.
Some newer photos on the eevblog forum show that those thin output cables are the same in 'genuine' 237s. So no more changes required.
All files I gathered for this project:
The circuit simulator I used: /