The $73.00 Mr. Haney (Pat Buttram) wants to charge Lisa (Eva Gabor) for the chemical test on her spot remover would be the equivalent of about $500.00 in the year 2021.
Doris Ziffel, i.e. Fran Ryan, and Fred Ziffel, i.e. Hank Patterson, argue about Fred's "war wound" and Doris says the only time he was wounded was when the MPs threw him out of a bar. MP is an abbreviation for "Military Police", which is the members of the military, particularly the Marine Corps and Army, who provide law enforcement services.
This is Fran Ryan's last appearance as Mrs. Ziffel.
This is the fifth and final appearance Bob Hastings makes in the series, and the second time he appears as the sheriff, the first time occurring earlier this same season in Charlie, Homer, and Natasha (1970). In past seasons, like this one, each of his appearances take on the role of a character in some service profession: a state trooper, an army officer, a telephone repairman.