Can it be repaired & renickeled? Yes. Parts might be available through www.gunpartscorp.com. Value varies w/ location but as is in my area about the same as a good steak dinner for 2. Value restored would be about double that. It can't be safely fired anymore so it becomes a collecter piece or keepsake... since it was your Grandads I'd make a nice frame for it & hang it on the wall as is to remember Grandpa by. If you want it restored Dave Chicone & Doug Turnbull both come highly reccommended although I've never used either one myself. If you get it restored post and 'after' picture, we love seeing great old guns.