The one screw basically.
The Smith and Wesson model 27-2 denotes that there was a second engineering change to the original model 27.The second change indicates that Smith and Wesson changed the cylinder stop,and eliminated the trigger guard screw.
No tirggerguard screw is the main one.
Smith and Wesson Model No. 2
The frame size of a Smith and Wesson model 66 is K.
Probably a Model 66
No such model listed in the Standard Catalog of Smith and Wesson. You will need to call the factory.
The Smith and Wesson model 19-5 was made from 1982-1985.
The smith and wesson model 18-3 was made from 1967-1976.
Smith&Wesson model 14
Via the screw.
No