Unknown Arabic | Ottoman With Die Clash?

Nice old hammered coin!
I can't ID, but I think the second pic is upside down.

Looks like 1223/16, Constantinople. Mahmud II, probably a Para(~13mm).
I suspect it's post mint damage, but a clashed die is possible.

A double-striking won't impart a backwards-and-incuse design on a coin. There are three ways to get all or part of the design on a coin backwards-and-incuse:

1. A brockage. This is where a normally struck coin isn't removed from between the dies before the next blank is placed on top of it; the first coin then "becomes the die" for the second coin. The resulting coin has a normal, undistorted side and a backwards-and-incuse version of the same side on the other side. No trace of the "normal" second side is visible in the incused area, because the coin never saw that die. The top pic on this web page shows a nice example of a brockage.

2. A die clash. This is where the dies smash together without a blank in between them; if neither die actually breaks from the impact, then parts of the obverse design end up on the reverse die, and vice versa. Coins subsequently struck with those dies end up with "mixed sides": obverses with traces of reverse design, and/or vice versa. The fourth pic down on the above linked site shows a die clash.

3. Post mint damage, colloquially known as a "vise job". This is where two normal coins are squeezed tightly or hammered together, partially transferring their designs onto each other. Counterfeiters sometimes make a "vice sandwich" with two real coins squeezing a blank slug placed between them; such a coin will bear a superficial resemblance to a real coin, only everything will be backwards-and-incuse.

To me, your coin looks most like #2.

(Edited for mising leters.)

Not sure. The quality of coins produced by the Ottoman empire went up and down alongside the fortunes of the empire itself. Which generally wasn't too good for most of the 19th century, with ethnic troubles, provinces demanding autonomy or seceding, European wars and other interference, and such like. In difficult economic times, the primary concern would have been to churn as many coins out as possible, and who cares how pretty they are. "Mint errors" would be common in such times, to the extent that error-free coins are worth more than normal coins with errors.

The reign of this ruler, Mahmud II, was just such a turbulent time. There were at least ten different series of coins during his thirty-year reign (1808-1839 AD).