The postmarks on this cover are very messy, but they are still legible,Maplewood NJ OCT 27 7pm.

The purple cachet reads "FIRST FLIGHT AIR MAIL VIA GRAF ZEPPELIN UNITED STATES GERMANY OCT 28 1928"

The 2c embossed envelope had the additional stamps added - 5 x 20c 'Golden Gate' and 2 x 1½c 'Harding'.
This has the distinction of being one of the most tatty covers in our collection. However, it, and the letter inside tell a historic story and it is worth keeping for that alone.