1980
There is no S&W with that Model number.
Call S&W with the serial number, and they will tell you when it left the factory.
50-500 usd
You need a gunsmith.
Asia and Africa
100-300
110.1667
661 is prime.
3√661 ≈ 8.711
661 x 1
661 x 36 = 23796
661 miles is about 1063.78 kilometres.