Roger Moore as John Vandergelt would later join the regular cast as Bret and Bart's English cousin Beauregard Maverick.
The plot is, rather outrageously, taken from Richard Brinsley Sheridan's classic 18th-century comedy play, also called "The Rivals" and first staged in 1775. - and the original author (who died in London in 1816) gets a credit, too.
John Vandergelt III quips regarding the $1,000 a week he is paying Bret that it is $40 more than the salary of the President of the United States. This is accurate as $960 a week ($50,000 annually) was the pay of the President from 1873 until 1909.
Bret's mention of Brooks Brothers is not an anachronism as the firm was founded in 1818.