The "Top Secret" and experimental field gun left at Stalag 13 was an 88 millimeter gun. That caliber was standard for German artillery in World War II.
Williams' cell has a 'Kilroy was here' drawing on the wall.
This was Paul Picerni's only guest appearance in the series.
This was Barbara Babcock's first guest appearance in the series. She was married to Jay Sheffield at the time; he also made guest appearances on the show but a different episode.