Any good reloading manual will get you started on assembling 38 special ammunition.
Best to let a gunsmith do this.
CTG stands for Cartridge
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.
100-300
Either 38 S&W, 38 Special, 38/200
The CTG. Stands for Cartridge.
Cartridge
Impossible to answer without the serial number.
CTGS = Cartridges aka ammunition.
What are you asking?
Yes
ctg = cartridge