The most important factor in the value of the handguns is the model. Assuming the Colt autos to be 1911 guns, you need to state whether they are government models, commander models, or officer's models. Also, whether they are pre- series 70, series 70, series 80, and if they are any of the "special issue" models. The revolver could be a Police Positive (one of several variations), Officer's Model, Officer's Model Match, Border Patrol, Trooper, or some other model.
The next most important factor in the value of these pistols is the condition. It is usually stated as the percent original finish remaining. Also of concern is whether there is any rust, freckling, or pitting, the condition of the bore, and whether there are any non-factory alterations of any kind.
The model must be correlated with the serial number in order to determine the age, as the same serial number will appear on many different models, sometimes decades apart.
Best suggestion is to order a copy of "The Blue Book of Gun Values". It has a section dedicated to evaluating condition, and a listing of nearly every common rifle / pistol / shotgun ever made, with a complete description of that model and a list of the variables / options to be encountered.