1968
100-600 USD
if your colt 25 auto is a model 1908 hammerless,it was made in 1927.
100-600 USD
100 to multiple thousands depedning on specifics
.380 1903
300-450 USD
depends of condition
Would need the model to answer.
I would need the Serial Number and Model of the Colt Semi-Auto marked on the barrel. Ivory usually adds $100-$150 to the price if done well or more is unusual with hand working.
To vague a description. Could be worth 500-5000.
The Colt .38 Auto, also known as the Colt Model 1900, was first introduced by Colt's Manufacturing Company in 1900. It was one of the earlier semi-automatic pistols developed by Colt.