Minor examples of this misprint error like yours might be worth a few additional dollar over face value when selling on a place like ebay but dealers dont buy these unless they are extreme/missing parts of the number. These are neat to see, but they aren't rare and not especially valuable. Collectors call this a stuck digit or some call it a gas pump error. On the two dollar bill it is most noticeable on the last 3 in the upper right serial number. The low serial number occurs because the numbers on the serial number roller gets stuck or jammed. For those of us who remember the non-digital gas displays, we can see why this misprint is sometimes called a gas pump error. A fun find.
1976 A (Boston) Star Notes are in the price guide as 18.50 for uncirculated, $10 for circulated EF40 condition individually.