Geeking out on Production Codes

[deweyinthehall]

So, when examining some 1973 Topps packaging recently, I came up a little confused.

There are two sorts of wax wrappers: the one with the catcher and the All 660 Cards red banner has a code of 0-451-90-01-3. The others without the banner (manager, batter, pitcher and catcher) are all coded 0-401-90-01-3.

These images are of three wax cases from 1973. The one marked with a 401 code should have held the 401 coded packs. I always assumed the one coded 452 held the 451 packs, even though those numbers should have matched. Recently in reply to my standing request on these boards for additional packing images, someone posted the third image which shows a case marked with a 403 code (stamped on the box rather than printed).

I can find no wax wrappers with anything but the 401 and 451 codes, but this case clearly held wax packs.

I know that Topps experimented with different distribution patterns that year.

Anyone care to guess what's going on?