If anyone didn't get it from themanwho, here is the answer to the original question:
Here: Jonas is "Skipper" Jonas Grumby, Roy is "Professor" Roy Hinkley, and Willy, well Willy is presumably the first name of "Gilligan", all characters from Gilligan's Island. The first two were actually named in the very first episode, Gilligan was never called Willie, but The creator of the series (Schwartz?) later said in an interview that that was to have been his name.
I've never heard "Lovey" called Eunice, but I'll take themanwho's word for it.