Mike Engle just found the 1957 newspaper page for this Paramount and sent me the tip on it.
I just checked google street view and sure enough it’s still there. Remodeled, yes, but still (barely) recognizable. It doesn’t seem to be in any of the diner finding guides or books, so I suppose this is a new find. I would love to see the interior. Anyone in the Chester area want to go check this one out?
Diner Hunter 
Guess I’m the most likely candidate. Nice find.
The other Rainbow Diner. (they owned two)
http://www.oldchesterpa.com/rainbow_diner.htm
Cool. Could be anything in there.
My uncle, Victor Andreoli, was an escaped con in the 1940’s. He was shot and killed in this diner.