You find a gunsmith who does blueing and let them do it.
You will have to call Colt with the sn to find out
no
open the cyl and number is on the frame
Revolver or semi-auto?
Proofhouse.com has Colt sn information.
Around 1921 for a 1903 colt hammerless .32 with that serial number.
about 1922
Yes.
made about 1915
It would be 90 years old. If it is a Colt 1903 hammerless .32 , it was made in 1921.
You must call Colt to find out.
100-1000 USD