Thanks Geo.
GIMP is free and can be downloaded from here.
http://www.gimp.org
I applaud your efforts to bring these old comics to your people in a readable form.
I've used GIMP off and on since it first became available.
One thing I enjoying doing with it is taking old photo graphs and transforming them into faux line drawings and watercolor paintings. GIMP even has the ability to add the textures of a canvas to complete the illusion.
Another was when I took still photos of the old west town we once rented as the setting for a film and converted these to sepia toned faux tintype photos.
We also converted some photos to line drawings and made up some convincing wanted posters.
I've also taken old damaged photos made near a century ago and used GIMP to restore these to like new appearance. I even added a button that had disappeared into a crack in the photo and completed the missing sections of a pocket watch chain.
Years ago some friends and I worked up a Superhero film that was part live action and part animation with scenes fading from live action to still and gradually into comic book panels.
The film didn't work out quite as well as we'd have liked, but we got alot of experiance in the various processes and had great fun doing it.
Our film group has since gone semi professional and snared a contract to put the Fighting Fantasy role playing game books on the big screen and to build a fully interactive version accessable on the net.
Thats a lot of work, and beyond my skills, but the team has attracted quite a bit of highly skilled talent over the years and I'm confident they'll get the job done.
There are still lots of free software of all types out there to allow those with limited resources to build the skills to allow them to go onto the more advanced methods and programs.