A Moment in Time is a limited edition cel set-up incorporating one or more original production cels.  (The meaning of the word 'moment' is said to have been that amount of time between heartbeats.)

In the case of The Old Sew and Sew, the one production cel was a moving part of a multiple cel set-up that was under camera for the 1966 production of Dr. Seuss' How the Grinch Stole Christmas.  This scene series is limited by the number of original production cels (61) and each set-up is numbered in sequence 1 through 61.  The other four cels in the set-up, most of which were 'held cels,' have been re-created from the film by expert ingkers and painters to complete the scene image.  ('Held cels' are production cels that are held under the camera for more than one frame and therefore the images do not appear to move.)