Found nicer Panama stamps as I dig deeper into the box.

Ohhhh Chile airplanes, those are cool.......

USA slogans, so indeed there are aliens living there ! Who do they report their addresses to ?

Are the rectangular cancels postmarks ?

The 3 cents is pasted on the words "postage due" and the 1 cent has a pre-cancel

That's all for now folks !

That air mail above is interesting. An embossed envelope, a 5-cent Monroe from the 1954-68 Liberty Series and a 1-cent Washington from the 1938-54 Presidential Series. It's interesting enough to have the two series on a corner (I found a few myself) but also on an embossed envelope combined with a 1960 cancel date - that's up to six years after the Presidentials were no longer being printed.

Interesting way to make the 10-cent domestic air mail rate of the day.

Must have been a late usage of old postage at the PO or possibly a stamp collector decorating a cover (which is more likely considering the source.)

I also have a bunch of pre-cancelled postage dues and I agree that it make no sense? I'm stumpped on that one. Nice box cancels on indestore's one post up there.

this one

Another box postmark ?

I'm curious why some airmail stamps seemed cutoff and were still allowed for use ? Especially the one on top left.
Should I leave them as they are ?

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Church Street Station ?