Lucille Ball's real-life grandmother's name Flora Belle Emmaline Hunt, is used as Lucy Carter's great-grandmother's name in this episode. The promissory note is made out to Lucy Carter's great-grandfather Frederick C. Hunt, which was the name of Lucille Ball's grandfather.
At the start of the episode, Harry is having a phone conversation with the office landlord, Mr. Praskins. Praskins was the surname of Ann Tyrrell's character Vi on the CBS comedy "Private Secretary" starring Lucille Ball's good friend Ann Sothern. There was an "I Love Lucy" / "Private Secretary" cross-over on the first episode of "The Lucy-Desi Comedy Hour" in 1957 and Sothern appeared as Rosie on "The Lucy Show."
It is revealed that Harry opened the Unique Employment Agency 29 years ago. Since the episode was aired in 1970, that would mean it was established in 1941.
This is the first and only time viewers see the Carter home's attic.
Craig's estimate of interest on the original $10 loan being more than $100 in 100 years is a very poor estimate. But he gets it right later on when he explains that $10 with a 10% rate of interest, compounded annually for 100 years is worth $137,806.12 (he rounds up to $138,000). Adjusted for inflation, $137,806 in 1970 is worth $895,163 in 2019.
Had the interest been compounded monthly the value would be $211,324.15. Had they not discovered the promissory note until 2020 (150 years later) it would be worth $16,177,178.
Had the interest been compounded monthly the value would be $211,324.15. Had they not discovered the promissory note until 2020 (150 years later) it would be worth $16,177,178.