Danzig 1930 - LZ 127 - Zeppelin - Baltic Sea Flight / Fahrt rund um die Ostsee : to Helsingfors , Helsinki drop - Michel 128 IIIa - Sieger 88

Good cover sent from Danzig on August 9th to Helsingfors
Helsinki drop / abwurf , on September 24th
Green confirmation stamp of the flight
A little bended in the lower part as in the picture
Stamp Breakdown
• Left: 10 Pfennig (Red, Danzig coat of arms)
• Center: 2.50 Gulden (Brown/Red, Grand coat of arms)
• Right: 40 Pfennig (Danzig coat of arms)
• Total Face Value: 3.00 Gulden (Note: 1 Gulden = 100 Pfennig)
The 3.00 Gulden total corresponds perfectly to the official postal tariffs for the 1930 Zeppelin Baltic Sea Flight:
• 2.50 Gulden: The exact, mandatory Zeppelin airship surcharge (Luftpostzuschlag) for a letter sent from Danzig to Helsinki.
• 0.50 Gulden (50 Pfennig): Paid the international surface rate. Since the basic foreign letter rate was 25 Pfennig, this 50 Pfennig fee covered a heavy-weight letter (second tier) or an automated registration/handling fee routinely applied to consular mail.
The franking is 100% correct and represents a mathematically perfect postal combination for this specific historic flight.

I can’t combine the shippings - non combino le spedizioni

IMPORTANT INFO:
Following a recent change in international sector regulations, specifically Articles 18 and 19 of the Universal Postal Convention, starting from January 1, 2026, it will no longer be possible to send items (goods with or without commercial value) using International Registered and International Insured services, which will continue to be used exclusively for sending documents.
It means that starting from January 1st, 2026, I will ship abroad only by "POSTE DELIVERY INTERNATIONAL