The old Model Cot Trooper was Colt's "budget" holster gun, intended for law enforcement use and sales to civilians not wanting to spend the money on the finer finished 357 Model or the Python.
The serial number is stamped in three places:
On the frame just below the barrel.
Swing out the cylinder and look at the frame just under the barrel.
Second, the number is stamped on the cylinder crane, opposite the number on the frame.
And third, the number is stamped inside the side plate.
The serial number will be a series of numbers, any letters stamped around the numbers are inspector's stamps.
Here's a brief history of the old model Colt Trooper:
The old Model Trooper is often called a "poor man's Python", since the Python is basically just a Trooper with a heavy lugged and ribbed barrel, a more polished and tuned action, and a better polished blue job.
It was made from 1953 to 1969 when it and all other of the old style Colt mid-frame revolvers were discontinued and replaced by the totally different Trooper Mark III.
The Trooper was originally available in .38 Special and .22LR.
It came with "service" hammer and grips or optionally with Target hammer and grips.
Finish was blue or bright nickel.
The .38 version came with a 4" or 6" barrel, .22LR in 4" only.
Early .38 Troopers had the firing pin mounted on the hammer, the .22 was always hammer mounted.
Later .38 and .357 Troopers had the firing pin mounted in the frame.
At the same Colt introduced the Trooper in 1953, they also brought out the Colt 357. That was both the caliber and the name of the model.
The 357 looked just like the Trooper, except it had the firing pin in the frame, and was to be Colt's premium holster gun.
The idea was, the 357 would be for those wanting the best, and the Trooper would be for police use and people wanting a "budget gun".
Things got complicated in 1955 when Colt introduced the "Super Premium" Python.
People wanting the best bought the Python, and people wanting cheaper bought the Trooper.
This left the 357 as odd man out, so in 1961 with about 15,000 produced, Colt discontinued the 357, changed the Trooper firing pin to inside the frame, and began to make it in .357 Magnum also.
The .38 and .357 Troopers were very popular with law enforcement, especially with Sheriff's departments, and were heavily used during the 50's and 60's.
The .22LR Trooper was intended to be a "trainer" for the center fire models, and these are fairly rare, with only about 2200 made between 1953 and 1969.
In 1969 the Trooper and almost all of Colt's old style revolvers were discontinued and replaced by a totally different type of revolver, the Colt Trooper Mark III.
The reason was, the old hand fitted and finished Colt's had simply priced themselves out of the market.
The Trooper models are high quality, strong, and durable guns.
They are a sleeper, considering that a Trooper is a good substitute if you can't afford a Python.
While the Trooper was intended to be a budget gun, like all the older Colt's it was a hand assembled and fitted revolver, of a type no gun maker can afford to make these days.
These days, Colt's "budget" Trooper is more finely fitted and finished than most any of todays revolvers.