My unique modification was to David White's 600 or 601 at his cabin in Newfoundland was to fit the light socket with a 13W compact flourescent spiral type household bulb.
I then cut the side out of a translucent milk jug that was headed for the trash to act as a diffuser, to even out the light output of this odd shaped lamp before it got to the condensors.

There was a slot just outside of the lamp house on the way to the condensors that was perfect to hold this diffuser. Heat was not a problem with this lamp.

This was done because electrical supply to the cottage is from a rooftop mounted 20W solar panel and charge controller powered deep cycle battery bank of two automotive sized batteries, that run a 12V to 120V ac invertor.

With the 13W bulb there was enough power to print for 3-4 hours, and also have a light on in the other room for my wife to read by or do a jigsaw puzzle.