AnonyMs: well, it wouldn't take much to find out what has happened to him if someone wants to take on the quest.
1. we know his real first name
2. We know what kind of business he owns
3. we know where that business is generally located
All someone needs to do is to look up in the Yellow Pages for that area the numbers of that type of business, call and ask to speak to the owner, first name of Grandpa's real first name.
I think he would be touched by the effort rather than consider it an intrusion on his privacy.
Marko, do you have word from him?