Not sure if I'm on the right forum to post this or not, but I'll start here.
U.S. Customs Service stamp/label scanned below shows no monetary amount so does that make it a Cinderella? However, with a SN, cancellation, etc., it must have been used to officially acknowledge something that went through Customs.
Can someone date it and/or shed light on its use? It has a "193" printed on the stamp below "Service" so I assume that to be a series number.

Thanks in advance for any help on this one.