Hello folks,i'm new to the forum.I have a 22 calibur pistol that belonged to my dad.I need some information on the gun.This is what i have, H&R model 922 serial number 175204 no letters on the serial number (what year is it). 6" round barrel 9 shot revolver cylinder pat# 1904 730 rear of cylinder #204 This pistol originally had walnut one piece checkered grip.The grip got broken years ago and i could only find the plastic grip for it.Is this gun a single action or dual action hammer and trigger ? The flat main spring was broke,i just got a replacement and need to know how to install it.Does the rounded end fit in the groove at the middle of the hammer or down low ? All help will be appreciated,Thanks !!