Where can you find parts for JC Higgins 22 caliber model 126.2830 pellet gun?

I'm going to try and help you with an answer. I know for a fact that the 126.2830 was made by Crosman for Sears. All Sears model starting with 126.XXXX were Crosman models. My catalogue list the model 126.2831 as a model 180 Crosman rifle not a gun, and I think yours is a variation of that model. See the #1 link below to see if it is a match.

If your is a Crosman model 180 rifle, then See the link #2 below. Crosman offers a service to locate repair shops that repair older Crosman models.

Link #3 is a parts list for the model 180