100-400 USD depending on condition, accessoires, box, manual.
300 USD or so.
Try e-gunparts.com
100-500 USD or so
@ 4"
I would start my search at Smith and Wesson first.
Your smith and Wesson model 686 is valued at 250-425 dollars depending on condition.
What is the value of a model 24 Smith & Wesson revolver with a 4" barel? It has never been fired.
Yes.
4.5 or 6 inches
You will need to ask a gunsmith
22LR
The best that I can do is say that the smith and wesson model 28-2 was made by smith and wesson from 1961-1969.