Wow - that would be amazing.
I don't know of specific assistance for hunters but there some options you should find helpful. Definitely go to disability.gov for information. It is an up to date, well organized site that is designed not for the disabled. And they are very specific about recommending resources of many kinds in your local area. You can find a number of them at Grants for Home Repair, and there is some more information specifically for seniors in Grants for Seniors.
If you are a member of the NRA or of any hunters' associations you could check with those as well.