Coronavirus Filler: The 1963 Mets Yearbook Cover

This one, sent to me by a reader a decade ago, is autographed.

Note that Mr. Met is wearing a cap with an orange brim, which was not a thing until the next century!   Is he also a time-traveler like 1962 Mets Baby?

Also, are they not sold on the name?  Why are they hyping that they are the National League Baseball Club?