I am starting this thread to see if anyone has an original one to use as an example so that reproductions can be made properly. Currently the vendors all sell a version of this sticker that has an "L" for the plant code, ie Lima Ohio. So far as I have been able to determine all 428 CJ engine assemblies were built at Dearborn Engine Plant, which would mean the ID sticker should have a "D".
I think if the sticker was on a 289, 302, or even a 390 from 1968 - 70 it would have a similar "D" if the engine was assembled at DEP.
Here's the reproduction 407J sticker: