Does the snare have a date stamp inside? The snare's number is pretty close to the set. I'm still going to go with December 1968. I have also noticed that most of the sets I have seen from this time period have snares that are close to the build of the set. If you look at how things were done closer to the Ringo explosion it's easy to see how chaos at the factory could make things look off as stuff was built quickly and stuff got shuffled around and possibly forgotten about until a later time after things slowed down. By late 1968 Ludwig was running things pretty smoothly and not so hectic and from what I have seen it looks like snares were made up pretty consistently with sets. Of course other factors could play into the snare being off from the set.
If the supra pile was getting low and a fresh batch was built and stacked with the existing pile then older ones could get pushed back to a later time. I'm pretty sure Ludwig did not treat drums like food and rotate the stock to keep fresh ones to be used up first. One thing I don't know is if Ludwig just made up the supra shells and then when one was needed they added heads and rims or if they were made up completely and picked from a stash when one was needed. Either way by 1968-69 it looks like production was pretty much caught up.
