On the first day of reissue (April 13th), people could take them to a Post Office & have them postmarked as proof they were from the
first day. I still have 10 postmarked from that day. Some may have a better value than others if it is a sought after Post Office mark. Yours are from the first day of issue. Keep them crisp & mint. Cheers. J.T.G.
From Wikipedia:
"On November 3 1975, Secretary of the Treasury William E. Simon announced the reissuance of the $2 note as a cost-saving measure; The new $2 notes would be available from banks on April 13 1976, Thomas Jefferson's birthday.[25] Series 1976 $2 bills were redesigned as a Federal Reserve Note. The note retains the same portrait of Jefferson, and the basic design of the obverse remains unchanged since 1928. The treasury seal and serial numbers are printed in green ink, replacing the red used on the previous United States Note. Since the reintroduction of the note coincided with the United States Bicentennial, it was decided to use a bicentennial-themed design on the reverse. Contrary to wide belief, the bill was not issued specifically to celebrate the bicenntenial. An engraved rendition (not an exact reproduction) of John Trumbull's Declaration of Independence replaced Monticello on the reverse. First-day issues of the new $2 bills could be taken to a post office and stamped with the date "APR 13 1976". In all, 590,720,000 notes from Series 1976 were printed."
