The serial number.
No
The smith and Wesson model 10 has the K service frame.
The 1966 Mod 60 Smith & Wesson in good condition is worth $1,200.00
Your smith and Wesson mod 4043 is running between 240-400 dollars depending on condition.
10-600 usd
1970
100-400 USD
It can be done, but, it is not recommended
Started in 1983
50-800 usd
50-400 usd
A fine revolver.