The first appearance of Tom whistling the semi-recognisable melody that a later documentary would actually admit that it really was based upon "Over the Raindow", from the MGM version of "The Wizard of Oz". Considering the episode is the one with the scarecrow dress, that may not entirely be a coincidence.
The first appearance of the Goods' cat called Shere Khan by Sam the costermonger. Shere Khan is the name of the tiger in Rudyard Kipling's Jungle Book.
First mention of Mr and Mrs Pearson, the Ledbetters' cleaner and gardener who are often mentioned but never seen.
Covering for inflation and pounds to dollars, £55 would be equivalent to over $400 in 2023.