While Parley Baer is credited as Mr. Bellingham, his last name is pronounced Billingham on the episode.
Steve mentions Uncle Joe crashing the Cannonball into the Pixley depot. That happened on the 4th season episode "The Rise and Fall of a Tycoon"
When Steve is getting his hair cut, Bert looks at a photo to pattern it after. One of the celebrities mentioned for the photo was Don Ameche. Interestingly enough, Don Ameche appeared in the previous episode "Steve's Uncle George" as Uncle George.
Grandpappy is never called by the name he's always been known by (that which he's even credited as), instead they call him "Grandpa" repeatedly.
The ending has literally no resolution to it. So the chimp comes back to the hotel? Where does it end up, then? Right back with the shifty salesman?
Dr. Craig claims she's known Uncle Joe for at least 2 years, but she first came to the Shady Rest just after Kathy Jo was born, and she won't turn 1 year old for another 9 episodes.
If you look closely, after the first time the Cannonball drops off the mail, after the line Steve says "Sam, the Cannonball stops right there", they show the Cannonball, except the picture is reversed (the lettering on the tender is backwards, and the right side of the coach has 4 windows...normally the right side only has 3, with the other side having 4)
Bert's Barbershop has previously been established as being in Pixley, yet this episode has it in Hooterville.
When Uncle Joe is landing in the water tank, the shot from above looks like a model, rather than the real tank.
The nighttime footage of the Cannonball looks more like a model train than a real one.
Apparently the premier of the movie "Wings" (see the previous episode "Wings") was a big hit, as it's still showing at the theater (when Dr. Craig arrives via the jitney). It's still listed on the marquee, with a poster that says "2nd smash week"
Sid Melton played Alf Monroe on "Green Acres".
The last time Burt Mustin appeared as Grampa Jensen, in the 5th season episode The Barber Shop Quartet his last name was spelled Jenson.
Owen Bush is credited as "Chauffer", which is actually the wrong spelling. It's spelled correctly in the guest list for this episode.
Uncle Joe says he hasn't fouled things up this bad since he ran the Cannonball into the Pixley depot. That happened on the 4th season episode "The Rise and Fall of a Tycoon"
Betty Jo mentions she was the one who found Dog and brought him home. This happened in the first episode of the 2nd season "Betty Jo's Dog"
At the beginning, when Dog is chasing the train, the footage is the same footage used on the closing credits, although it's a bit longer.
A close-up of Steve and Betty Jo's marriage certificate is shown in this episode, and shows the date as June 7, 1967.
Burt Mustin plays Grandpa in this episode, although it's not specifically stated whether he is Grandpa Miller, or Grandpa Jenson (as he appeared in several other episodes). A mention is made of Grandpa Miller getting the coffee and doughnuts though. He plays the same exact role as Grandpa Miller, complete with hard of hearing and playing the cymbals in the Hooterville Volunteer Firefighter Band.
A reference is made to Uncle Joe not being able to stop the Cannonball and running into the Pixley depot. This happened on the 4th season episode "The Rise and Fall of a Tycoon"