Ideally the gap on a revolver, including the Colt's is right around 0.005".
The range should be about 0.004" to 0.008".
Today's S&W says that a gap of under 0.012" is in spec. In the old days they held to the 0.004" to 0.008" standard but have loosened it up quite a bit.
If your Colt is a .38 Special, the guns actual model name is the Colt Police Positive Special.
The Police Positive was the same gun only made with a shorter frame and cylinder for use with the old short cartridges like the .32 and .38S&W.
As for the Colt's complexity, you're exactly right.
The old Colt action is extremely complicated and the critical working surfaces are tiny, to the extent many people don't even realize they are a critical working surface.
Almost all action parts were hand fitted at the factory by a master fitter stoning and bending parts to get it assembled and adjusted to operate correctly.
In the Colt, every part performs at least two totally separate functions, neither of which is related to the other.
Make a small change "here" and something totally unexpected happens over "there".
The old Colt action is somewhat rightly known as a "watchmakers gun".
This is why so few of todays gunsmiths either know how to work on the old Colt action, or are willing to take one in.