“Don’t stand outside and be miserable; come inside and get fed up” (restaurant sign)

“Don’t stand outside and be miserable—come inside and be/get fed up!” is a one-line food joke that appeared in restaurant windows across the country by 1965. The joke is of unknown origin.
 
   
Google News Archive
23 July 1965, Milwaukee (WI) Sentinel, ‘This Would Drive Us Buggy” by Buck Herzog, pt. 1, pg. 11, col. 1:
And Joe Kaye reports a sign on a Lake Geneva (Wis.) restaurant reads: “Don’t stand outside and be miserable. Come in and get fed up.”
   
12 November 1965, Ada (OK) Evening News, “Today’s Chuckle,” pg. 1 (box):
Sign in a cafe window: “Don’t stand outside and be miserable—come inside and be fed up.”
 
16 November 1965, Mason City (IA) Globe -Gazette, “Standing on the Corner” by Ken E. Berg, pg. 17, col. 2:
Best sign we’ve seen of late (in a Montana cafe window): “Don’t stand outside and be miserable—come inside and be fed up.”
 
21 November 1965, Los Angeles (CA) Times, “Roundabout with Art Ryon,” pg. B45:
One of the parking attendants at Jack’s at the Beach wears a big button that reads: “Don’t Stand Outside and Be Miserable. Go Inside and Get Fed Up.”
   
8 December 1965, Chicago (IL) Tribune, sec. 1, pg. 20:
In a cafe window: “Don’t stand outside and be miserable; come inside and get fed up.”
 
18 April 1968, Los Angeles (CA) Times, pt. 1, pg. 4:
At both Du-Par’s and the Salem House: “Don’t stand outside and be miserable- come inside and be fed up.”
 
Google Books
August 1984, Boys’ Life, pg. 68, col. 1:
Sign outside a restaurant: Don’t stand outside and be miserable. Come inside and be fed up.— Rod Young, Jasper, Ind.