While there was no Empress Carlotta (spelled with two "T's"), there was an actual Empress Carlota. Charlotte of Belgium (1840-1927) was a Belgian princess who became Empress of Mexico when her husband accepted the Imperial Throne of Mexico and reigned as Maxmillan of Mexico. As Empress, she took the name of Carlota, which is Spanish for Charlotte. As mentioned in the episode, Carlota was a very paranoid person most of her life, once accusing Napoleon and his wife of trying to kill her with a drink, she eventually did go mad due to her paranoia.
Mary Tyler Moore (Laura Petrie) and Gavin MacLeod (Maxwell Cooley) would later co-star as Mary Richards and Murray Slaughter in The Mary Tyler Moore Show (1970).
The roles of Rob's parents Sam Petrie (Will Wright) and Clara Petrie (Carol Veazie) were recast in later seasons with J. Pat O'Malley and Tom Tully and with Isabel Randolph, respectively. While the actress portraying Clara Petrie grew slightly older with the change (Veazie was born in 1895, Randolph was born in 1889), the actors portraying Sam Petrie grew progressively younger (Wright was born in 1894, O'Malley was born in 1904, Tully was born in 1908).
$35, the price of all the jewelry, would be about $306 in 2024.