Dimensions:
Date code: none
Lids: either MEDCO, Everclose, GEMCO, Utilities Specialties or HALCO.
Hole for spoon: yes
Backstamp: These pieces do not carry the traditional Akro Agate backstamp, but have a single number, which we've been told identifies the mold with which the piece was made.
Photo of the lid's backstamp on the pink bowl:

Photo of the backstamp on the pink bowl, ostensibly the mold number: