There has long been a school of thought that if a Colt cylinder is retarded in any way, like clamping a pipe wrench on it, it will not "carry up", resulting in a great disaster in which whole counties will be wiped out. I suspect that some of this silliness originated with folks who, for a hefty fee, would "properly time" the gun.
In fact the Colt mechanism will rarely lock up if the gun is cocked slowly in single action UNTIL the trigger is pulled. When the trigger is pulled, the cylinder will carry up and lock before the hammer falls and the firing pin contacts the primer.
So to see if a Colt is "in time", simply fire it normally. If the firing pin strikes are centered in the primer, there is no problem and nothing to worry about.
Today, gunsmiths who will/can work on those guns are thin on the ground. Even Colt won't work on some of the older ones, as parts are no longer available or being made and their skilled workers are long gone.