Barring Dfariswheel hanging out his single and announcing he will work on the older Colts, it behooves us to learn how they function, are disassembled and reassembled. I am currently working on an old Colt Police Positive 38 S&W. The manuals are out there-Kuhnhausen's, e.g.- the tools are there, all we need is the patience and the willingness to learn. I like to quote the words of the late Professor Richard Mitchell, aka The Underground Grammarian. In an essay in which he held that the US education system had some responsibility for Three Mile Island and the failure of the Iran Hostages Rescue Raid, he noted that a helicopter is a very complicated thing, an nuclear reactor even more so-but they are both finite things-"the human mind CAN know them completely."
That is a good perspective to have from the viewpoint of a person who wants to learn about Colts. However, from the perspective a person who wants a robust, trouble free, easy to fix, easy to modify, easy to tune, handgun, then they would be better off opting for a S&W.
As in my experience with a VW Beetle, the mechanics thought they were great because they could put the engine on a bench to work on them. However, from an owner's point of view, the reverse gear would wear to a bevel and could not be held in gear, the heat exchangers would rust-out, the front end was very difficult to keep in alignment, etc.
From an owner of a Colt view, I would rather they did not go wrong in the first place and if they do, I would rather that it would be easy to find parts, and a competent gunsmith that could fix them. As each day passes, there are fewer of both.
I think I understand why the double-action Colts were dropped by Colt...it was about time, and it was the logical thing to do due to its lock-work. At some point, when beating a dead horse, one will almost always come to the realization that the horse is dead. I think Colt came to that conclusion.