The shooter and the fact it is DA
Features.
By the features.
The user.
No
Experience, features, reference books.
Safety measure
No way to answer without detailed information on all markings and features.
Impossible to answer without a detailed description of all features.
Smith and Wesson Model No. 2
Impossible to tell model from only the serial number. Detailed description needed of all features, caliber, etc..
No serial number provided.
Depending on age, condition, features etc., it can range from 100-1000 USD.