Your Colt K model frontier scout .22 pistol was made in 1964.
No serial number = no answer.
The 1959 Colt frontier scout pistol, serial number 48899F is valued at $900 in excellent condition. In fair condition, it is valued at $400.
To answer the question we'll need to know more about this pistol. Is it a revolver or a semiauto? What model and caliber? I found a Colt frontier scout .22 with that serial number made in 1962.
Depending on the serial number ,between 1970 & 1977 for the peacemaker .22 model
about 1958
The lower the serial number the younger the pistol is
Could not find a Colt frontier scout with serial number 56599P, but a Colt frontier scout with serial number 56599F was made in 1959.
The PY in the middle of your serial number dates your pistol to 1982.
From the records I have, the Colt frontier scout .22 Q model was produced in 1967. (210500F-223199F) about 1967
The Colt Frontier Scout with that serial number was made in 1965.
In order to tell how old your Colt 25 semi auto pistol is, you will need to offer the serial number. This number gives you an idea of when the pistol was manufactured.
it might be a model from 1975