Based on proofhouse.com ,that bisley was made in 1913.
Made in 1911.
A Colt Bisley with that serial number would be 103 years old having been made in 1907.
The Colt Bisley Model in .32 WCF with serial number 257473 was manufactured in 1910. Colt's serial number records indicate that production of this model occurred primarily between 1894 and 1915. For a precise year, you may want to consult Colt's official records or a reputable firearms historian.
Nearest I could find with that serial number was a single action army & bisley (pre war ) made in 1895.
1897. IMO, worth spending the money to get it lettered by Colt
about 1902
About 111 years old, made in 1899.
10-10000 USD depending on specifics.
colt fronter six shooter serial # 1186654
The Colt 1911 government model with that serial number was made in 1919,
A Colt 1903 hammerless .32 with that serial number was made in 1919.
Your colt was made in 1966.