Since this one-off TV special teams Andy Griffith, Don Knotts and Jim Nabors, you would be justified in assuming that they appear here as their Mayberry characters: Sheriff Andy, deputy Barney and grease-monkey Gomer (who left the lube rack to join the Marines). You would be justified, but you would be mistaken.
This is an interesting attempt to give three familiar performers a chance to demonstrate their acting abilities in roles outside their usual range ... though still firmly within the bounds of comedy, of course. No dramatics here. Basically, this special is a bunch of unrelated skits, with no recurring characters.
One skit, early on, is astonishingly similar to a couple of the later but more famous sketches by Monty Python's Flying Circus: the notorious dead-parrot sketch, and (even more so) the cheese-shop sketch. Don Knotts plays the feckless customer who wanders into the General Lee Dry Goods Store, run by Griffith. It got that name because, whatever the customer wants, "we General Lee don't have it", Griffith explains smarmily. Anyone who saw "A Face in the Crowd" is aware of how effective good ol' Andy can be at playing sleazeballs. He's very good here, but the sketch isn't funny. Still, it eerily prefigures Monty Python's cheese-shop sketch: Griffith seems to be maintaining a shop for the express purpose of not selling anything.
The climactic sketch here is deeply weird: a family picnic, starring Griffith and Knotts as husband and wife(!) and Nabors as their bratty little son, who seems to be about eight years old. Knotts, in elaborate female disguise, is actually far more convincing here as a woman than Nabors is as an underage boy. Unfortunately, the material isn't funny: husband Andy Griffith and wife Knotts (Donna?) get into an argument over the fact that she's older than he is (they agree that she's older, but disagree about how many years), while "Junior" Nabors keeps trying to show them the various dead skunks and other roadkill he keeps finding.
Since each of these three performers was hugely successful playing one particular character (well, maybe two in Griffith's case), and since the teaming of the three of them here was certain to remind audiences of those three Mayberry characters, I felt that they deserve some credit for attempting to expand their range here. Unfortunately, the script material is fatally unfunny. You'll get a few seconds of shock value from seeing Knotts as a passable woman and Nabors as a (not so passable) little boy, and a few more seconds' shock value from realising how closely the Monty Python cheese-shop sketch (written after this special first aired) resembles the General Lee sketch performed here. That's about all you'll get, though. My rating for this one: a mere 3 out of 10. These fellers did better work elsewhere.