I can't remember her real name but I'm pretty sure she was dating Elvis just before he "allegedly" died...
Gunilla Hutton, miss Goodbody was having fun with Nat King Cole and she also played Billie Jo on Juction. Donna Douglas (Elly may) messed around with Elvis, during the filming of Frankie and Johnny she became his girl and was under the impression that she would marry Elvis.
Hooterville is supposed to be in Illinois, there was a Greenacres episode that actually showed a map of Illinois and pointing where it was. The Clampetts came from the Ozarks, but for some time CBS had them coming from Tennessee but that didn't work out for some reason.
Another bit of useless trivia - the largest audience in television history until the 1967 was the Beverly Hillbillies thanksgiven special which I think aired in November 23, 1966 and incluided the entire cast of all three shows. This was bumped in the record books by the last episode of the Fugitive where Richard Kimbal found the one arm man - August 29, 1967.