The interlocking NY can be difficult for airbrushers to pull off, as can be seen on Matt Keough's 1983 Topps Traded card.
Interestingly, it was at least occasionally difficult to accomplish on the actual helmets. See Bob Geren's 1990 Leaf card, for example.
Here's a close-up, where you can see that both the N and the Y are rather misshapen.
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