When they turn on the radios, they instantly come on. The radios at that time were tube, so they had to warm up before they would come on.
When Willie Hawkins enters the bar for the first time, he accidentally calls Cassie "Kasidy". Incorrectly regarded as goof: While you may think it sounds like Kasidy, listen closer: he is actually saying Cassie, just with an unusual inflection, as he is shouting her name in joy from across the noisy room: he stresses the second syllable and with a pause before it: "kas'SEE!". (The CloseCaption has it as Cassie too.)
In the restaurant, when Benny is startled by Worf/Willie Hawkins, he is grabbed on his right shoulder by Worf's right hand and arm (slightly bent at the elbow). But when the camera cuts to Worf, he is extending his left arm. When the camera cuts back to Benny, you see the same right hand and arm and elbow, which Benny then turns and flicks off.
When Herbert threatens to quit, he packs a '60s-era Hugo Award rocket. While the first Hugo statue for science fiction was awarded in 1953, the rocket was smaller and the base was larger.