1931 Airmail Registered Cover - Teheran Iran To Norristown PA USA

Found this interesting cover 1931 Airmail Registered cover - Teheran Persia (Iran) to Norristown PA USA lurking in one of my old cover albums

Don

Very Nice! And with such a neat variety of stamps.
Makes you wonder the history of the cover.
It seems to have cost a lot for the sender.

My, that's a nice cover. Philatelic, very busy, but it's legitimately gone through the post. I don't suppose one of our members will know how much the airmail rate and the registration fee was? Also, I can't remember how many chahis in a kraan...12? 16?

There was no airmail across the Atlantic in 1931 so this was not flown from Tehran to Norristown, Pennsylvania. This would most likely have gone by airmail from Tehran to Cairo where it would have been put on a ship going to the US, or possibly it could have been put on a British Imperial Airways plane to the UK where it would have been put onto a ship to the US - whichever the postal authorities along the way thought would be the fastest when they received it. Once in the US it could have been forwarded to Pennsylvania by either train and then truck, or by airplane and then truck, whichever the postal authorities thought would be the fastest when they received it. Unfortunately there are no intermediate postmarks or other official or handwritten markings that can tell its exact route, and how much of it beyond the ship route across the Atlantic was by aircraft vs. ship and other means of transportation.

Interesting that the first US postmark is from Philadelphia not New York as one might expect.