When they examine the metal of the bullet with a microscope, they call it a honeycomb pattern. A honeycomb pattern is hexagonal pattern. The image they are looking at is a square pattern.
After Minns makes $400,000 on speculations, he wires money to the other conspirators working on the spaceship. It is mentioned that he sends money to PFC Hadley via the "Kansas Bank of Wichita." A fictitious bank is not a problem, but every time the action cuts to Hadley's work the caption reads "Wichita County." Wichita, Kansas is the county seat of Sedgwick County. There is a Wichita County in Texas, but given the Kansas bank this was obviously just a mistake.
With $500, Lt. Philip Minns requests his broker to buy 2000 bushels of wheat. In 1964, the lowest price for a bushel of wheat approximated $1.40. For $500, he could only buy about 157 bushels if he caught the lowest price.
Closing credits misspell the character description for Leon Askin as "Shop Superintendant." The correct spelling is "Superintendent."
At about 44 minutes in, the strings that lift the anti-gravity device can be seen.
At about 8:26 the reflection of a studio light and stand is seen in the glass door of the bookshelf/cabinet (right of screen).