Kingsnake.com has listings for older animals. Some are retired breeders. Many pets stores take in people's pets for re-sale. I've seen older snakes on Exotic Pets Las Vegas, and LLL Reptile multiple times. Your closest exotic vet might have a cork board where you can hang a "wanted" flier. All that said, maybe contact your local Animal Control too. You could end up with some sad hopeless cases, so I would be specific about what I wanted, but you would be surprised how many perfectly good pets end up in shelters because their owners either die or get put into nursing homes. Our local AC lady knows we keep snakes. Because she asked, I specifically told her we do NOT want her to contact us!