Model numbers came into use @ 1957. Model numbers are stamped in the yoke area. If it's before 1957, the only way to id it is to provide a detailed description and pictures.
The Model 16 was not made in 38 Special.
No way to answer without the serial number which is on the butt.
No way to tell model from jus the serial number.
No serial number provided
Yes
J frame, usually in 38 special
Overall length The 38 special is a stronger cartridge. If you have a .38 Special revolver it can still shoot a .38 S&W but not the other way around.
It is a K frame. No way to tell exact model from just the serial number. Most likely a Model 10.
The gun is likely a Harrington & Richardson (H&R) model 925. The caliber is .38 Smith and Wesson (S&W) special, not to be confused with .38 special (SPL). You must shoot the .38 S&W ammo, not .38 spl.
IT IS A 1957 MODEL OF THE COLT DETECTIVES SPEC .38
25-65 USD or so
Impossible to answer without knowing who the maker is.