The next item to change was the build platform. The standard one is an Acrylic plate covered by masking tape and I really dislike it. The bed adjustment screws also needed an improvement. There are two basic ways to add a heated bed:
1. Use low voltage high current heater. It is usually an etched pattern on a PCB and an external high current DC power supply.
2. Use a mains operated heater and no separate high current power supply is needed. Of course working with mains has additional risks but so does wiring a high current power supply that also needs to be connected to the mains.
I obtained a boro-silicate glass plate of the correct size and since I already had 120V heating pads that can be attached by a high temperature adhesive, I attached them to a matching size aluminum plate to evenly spread the heat since glass has poor heat conduction. I added a thermocouple sensor to the glass itself and the heaters are controlled by a commercial digital PID controller that I also happened to have.
After adding new mounting and leveling screws I am now very happy with that section.