This is an interesting and enjoyable episode, but not too memorable. Watching Andy as a flim flam salesman is NOT typicial of this series, and goes to show us 1) that the show was still in its formative developing stage with Andy's character and 2) that Andy is indeed not perfect.
This episode is actually quite well acted, it's just that the story tends to meander a little too much (even for Mayberry!) and the directing is not as "tight" as usual. Opie actually ends up with the best scenes in this episode!