Final appearance of Elizabeth Patterson as Mrs. Trumbull.
Desi, Jr. has long talked about the identity crisis he had growing up where everyone thought he was "Little Ricky." Desi, Jr. also reports that, when Keith Thibodeaux was hired for the sixth season, he tried so hard to be better than Keith at whatever he could. the reason Desi, Jr. got into music (drum playing, specifically) was part of his plan to beat Keith.
The range in Lucy's kitchen which was always electric is changed to gas for this episode to accommodate Fred turning off the gas. A couple episodes later it's back to electric.
This is the last Ricardo-Mertz feud we get to see (though they do briefly feud in Lucy Does The Tango).