can't be answered without a DETAILED DESCRIPTION OF ALL MARKINGS, caliber, barrel length, finish, sights, grips, box, papers, etc..
50-125
10-100 usd
I am not familiar nor do I know of an H&R Model 943 "pistol" - could this be a Model 949 revolver?
Given the poor description; 1-100 USD.
"M" prefix indicates 1952
Try e-gunparts.com
Impossible to answer without the serial number.
midway usa has a pistol grip that fit h&r and NEF shotguns (shop by make and model )go down to h&r on list and go from there
Gun shop, gun show, e-gunparts.com
"C" prefix indicates 1942
25-125 USD or so
25-50