Dating antiques by patent number
Here, again, examining the details of the dispenser stem is helpful.
The original footless Pez dispenser stems have a very shallow low profile spine (projection that runs the length of the stem) on both the front and back of the stem.
Also, in most cases, a newer footed pez dispenser which has had its “feet” shaved off can be recognized easily in this way.
A word of caution, though, is necessary since there have been identified some legitimate footless Pez stems (Santa C, Snowman B, Witch C, and Pluto with movable ears on 3.9 patent stems) that have a raised spine.
It is safe to say that if you encounter a footless Pez on a stem with a 4.9 or higher patent number it is undoubtedly not a vintage Pez dispenser.