The photograph Waverly shows of Gervaise Ravel leaning out a car window with Buffington in the background is actually a still from The Giuoco Piano Affair (1964).
When Anne Francis is receiving the video communication at toward the end of Act 2 the close up shows the video on a 12 or 15 inch rectangular Dage monitor, but the screen associated with the communications system is a larger 21" round tube monitor on the equipment wall.
Solo subdues the guard while rescuing Marion Raven, and lays him down in the hall. When Solo turns away as the lock on the door begins to burn, the unconscious guard is missing.
Horth kills an intruder and then uses his foot to turn the man over. You can see that the dead soldier is clearly rolling over on his own.
A helicopter drops off Solo, Kuryakin and Raven. When the 'copter lands, you only see Solo, the pilot and a dummy in the back, which ends up slumping over. The next scene shows Kuryakin and Raven getting off the chopper.
When they are at UNCLE headquarters discussing the gas, Mr Waverly drops a computer card into a slot and it clearly shows the card dropping to the floor instead of going into the machine.
While Horth struggles against the guards in the base, one of their machine guns is pressed against the wall, causing it to bend and reveal itself as a rubber stunt prop.