Was demolished several years back. Real name, the "Hawthorne Grill", that Honey-Bunny and Pumpkin held up.

Interior of it and the one where Nick met Cal are pretty generic. Looks similar to quite a few older Denny's I've been in, so a corporate layout.
I imagine the set designers were going for this look as an homage to PF . Tarantino's a big fan of zombie chic. Played a Z in Robert Rodrigez' "Planet Terror". Maybe he'll cameo as a walker in an upcoming ep, so this might be a foreshadowing.

 

HA ! I get it ! It's a zombie restaurant ! Calvin should have been eating some 'pumpkin' pie !