It was not until the HSCA used audio analysis to suggest an early missed first shot that anyone seriously considered that the first shot missed. If you can find any serious publication prior to the HSCA report in which it was seriously proposed that the first shot missed I will stand corrected.
This snip from the WCR seems to me to be the WC seriously considering whether or not the first shot missed:
Yes. But there is a difference between what the WC members thought and what they said in the WR. They said in the WR that the SBT did not matter and was not essential to their conclusion. But Commission counsel and at least 4 members actually thought it was. My point was that despite saying that the first, second or third shots may have missed, it was clear from McCloy that he thought the first shot struck both JFK and JBC and was the only shot to strike JBC. Arlen Specter also thought this because he concluded that Connally was incorrect in thinking he was hit by the second shot. Here is what he said in Life Magazine in 1966:

All Connally had said is that he was sure he heard the first shot before he felt the impact of the second shot. He never testified that he saw JFK hit by the first shot. So by saying the Connally was incorrect was saying that Connally was hit by the first shot. That was the clear impression left by the WC until the HSCA in 1978 suggested that the first shot may have been much earlier and missed, based on the acoustic evidence (which we now know was wrong).