45 ACP
Not factory. 10-100 USD
You will need to call Colt for a definitive answer.
You need to contact Colt
10-10000 USD depending on specifics
Around 1917. Colt and S+W each made around 500,000 for the US military when the US went into WW1. If you need an exact date, check online for one of the Colt databases that go by serial number.
You need to contact Colt for a correct answer.
MODEL 58321
you will need model name.
You will need to call Colt
You need a good gunsmith.
Would need the model to answer.
Maybe. You need to figure out which .38 your Colt is chambered in. .38 Short Colt and .38 Long Colt guns will not chamber a .38 Special. .38 Colt Special is the same as regular .38 Special. If you cannot tell which caliber it is you need to take it to a gunsmith and have him tell you.