[philman_36]

Yes, that is Correct. There should be a 1980.
Thanks for answering the question. My apologies for my insistence. There are some claiming that the stamp didn't have to be four numbers.

Do you think this is a forgery or not?
I believe there is very strong evidence of it being a forgery. Namely because of the missing 4 number year stamp.

So let me ask you this, you being an engineer and all...
If one were to "roll" a flat stamp, as you suggested earlier, then isn't it logical that the outside edges of the stamp would be what was worn away instead of what was in the middle and which would have an even pressure exerted upon it?

[philman_36]

If a single, sharp downward strike was used, as is the usual method for such a stamp, then I can understand the outer edge being a lighter inking and somewhat ineligible, especially if the stamp were not cleaned properly before storage.
The outer ring of the stamp would be used far more often than the individual inserts in the middle and would wear down quicker. The inserts are changed more often and would remain clearer if a downward strike were made.

I just can't see your "rolling" method and explanation as viable. That type of stamp simply isn't used in the manner in which you prescribe.