In the establishing shot of the final scene when Sam/Jimmy returns to the docks to get his job back, It's the previous long shot of Sam and other unloading the bag from the freighter. You can recognize Sam adjusting his hair and cap.
Near the beginning when we see Jimmy's reflection in the mirror, part of Sam's arm and sleeve can be seen for an instant.
While Jimmy (Sam) and his brother share their lunch on the pier at work, the brother grabs an individually wrapped Twinkie from Jimmy. Twinkies did not come individually wrapped in 1964. You could only purchase them in a twin-pack.
The poster in Corey's room of "The Mighty Thor" was released in the late 80s, close to the time the episode's original air date in contrast to 1964 when the episode took place. The logo on the poster was designed by an artist at Marvel Comics sometime in the mid-80s.
When Sam (as Jimmy) drives back to the docks and his nephew Corey follows on bike, they pass by street name signs that are blue with white lettering. This color combination wasn't in use in the United States until the 1980s. Most street name signs were either black on white or white on black in 1964, when this story is set.
When Frank says "Toughest day of his life was when he had to put you in Wayside" the audio is clearly dubbed as the lips say "Bayside", not "Wayside".
When Sam drives off in his brother's truck, a body of water is in the background, supposedly the San Francisco Bay (he's in Oakland). The actual Bay is only a couple miles wide, but here no land is visible on the other side; it's clearly the ocean.