The $300.00 Oliver Douglas, i.e. Eddie Albert, lost due to the old mail fiasco, would be worth about $2,492.00 in the year 2022.
The old mail for Fred Ziffel, i.e. Hank Patterson, was dated August 12,1917, 51 years before this episode aired. It was his draft notice for World War I. Hank Patterson was born October 9, 1888, and would have been 28 years old when the draft notice was sent.
A mere 28 families in the Hooterville valley use the post office at Drucker's store. The U.S. Post Office demands a minimum of 32 to keep an office open.
Lisa dry-cleans Oliver's suit by putting it in the washer, without water, and covering it in detergent.
There's no real evidence that Will Rogers ever made the "grouchy congressman" comment that Mr. Haney attributes to him, but Will Rogers was famous for humorous quips about politics and politicians, and the quotation smacks of something he would say.