Paul Reed, who plays Henry Fregosi, had previously worked with both Fred Gwynne and Al Lewis in "Car 54 Where Are You?"
When Marilyn opens her gift from Lily and comments on how beautiful it is, Lily says, "It's a silk purse made from a sow's ear!" This is a play on the proverb, "You can't make a silk purse out of a sow's ear," which means it's impossible to make a quality product out of inferior materials.
The character of automaker Henry J Fregosi, is a play on Henry J Kaiser, who developed the Henry J, an American automobile built by the Kaiser-Frazer Corporation and named after its chairman, Henry J. Kaiser, in the early 1950. To improve slow sales, in '52 Kaiser sold, through Sears, a re-branded "Allstate", which was a Henry J with some added options, such as trunk lids. He also said he once cursed a specific brand of car, "You ever heard of the Edsel?" That was the Ford Edsel which had a weird design and didn't sell much and was soon off the market.
The Fregosi Emerald was likely named after Jim Fregosi a very popular player for the California Angels at the time.
The 'Fregosi Emerald's curse might be explained by one of the folk stories told by the 16th-century French historian Brantôme. He was impressed by the emeralds brought back to Europe from the Americas by Spanish explorer Cortés. On one of the most notable emeralds, Cortés had a text engraved. Brantôme considered the act of engraving such a beautiful and simple product of nature a sacrilege and the cause for Cortez's loss of an extremely precious pearl, and even for the death of King Charles IX of France, who died soon afterward.