Need more info in order to help. From your question it is S/N 11848 but the barrel markings are needed to determine what model you have.
your 45 pistol was made by Ithaca in 1945. if your slide reads Colt that indicats someone put a colt slide on your Ithaca frame, which is not unusual in the military. value depends on over all condition.
value depends on over all condition. made about 1893
Have it checked over by a good gunsmith before you attmept this.
Walther PP copy of the GDR. Region of Magdeburg.
That particular colt official police .38 with serial # 569014 was produced near the beginning of 1931. ( 569000 - 572999 ) The T would possible stand for the inspector's mark. I have a colt DS from 1930 and it also has a T over the serial #.
Made by many different makers over the past 100 years
Colt has done many special orders over the years. You will have to call them to find out.
Have it checked over by a gunsmith to be sure.
Your question is basically not answerable. Since it began making firearms over 150 years ago, Colt has made hundreds of thousands of products. Colt also made items which have no relation to firearms and had serial numbers. If you provide a detailed description of all markings, caliber/gauge, barrel length, handgun or longgun, etc.. an answer might be possible
For each serial number - are you talking about a rifle? If so, is it a bolt action, pump, or semi-auto? Pistol - what caliber? 22,25,32,380, 9mm? Shotgun - Over/under, pump, semi-auto? What gauge? 12, 16, 20, 410?
Sometime in 1969. If you call Colt's Mfg., Inc. and give them the serial, they can give you the specific date. They will do this over the phone, while you wait.
Have a good gunsmith check it over first.