Here are some photos my REC-29 upgrades.
My new cables - a standard power cord, 4 3-pin Molexes for +, ground and -
The connections of those cables inside the REC-29..
The silicon rectifier and surge protection resistor.
The new filter capacitor - 220 MFD at 200 volts
The strapping to get me the lowest DC voltage - 122 volts.
The front of my 60 mil loop supply to run on that voltage.
The back of that loop supply, The 1.5K resistor runs hot enough, that I used one that could be bolted to the panel for heat sinking.