Your colt python was made in 1961.
@35 years old
Depends on it's serial number.
36 years old
Colt never made a Model 142677.
A Colt python with that serial number would be 43 years old, made in 1969.
The Colt python with that serial number was produced in 1961 making it 48 years old or the Colt trooper in 1958 making it 51 years old.
About 36 years old, made in 1975.
Colt never made a model using that model number.
Once you have it's serial number, go to www.proofhouse.com and look it up.
You will have to call Colt with the serial number to find out.
100-1000 USD or so depending on specifics
what model ???