Can't be answered without knowing who made it.
No difference. CTG is the abbreviation for cartridge. A revolver marked 38 Special CTG, or .38 S&W Special CTG is simply indicating that it is chambered for a .38 Special cartridge. This IS different from .38 S&W, and older, shorter, fatter, less powerful cartridge.
CTG stands for Cartridge
Your Colt Trooper .38 special CTG # 68404 was produced around 1968. made 1968. value depends on condition
Over 100 years old
@ 23 years old
No such sn for a 38 spl
Impossible to answer without the serial number.
Early to mid 80s
Cartridge
Depends on how old the revolver is.
What are you asking?
@ 58-59 years old