It's a 25x25 QR code.
It's best to try to reconstruct the QR code since we can get useful information from it than an address prefix and suffix. It'll let us find even addresses that are not spent from.
Since the address parts were presented in monospace font, we can also get the length of the address by measuring the pixel distance between each character, the distance between the first and last characters, and dividing them together. And this makes our lives easier because an address can be 25 to 34 characters long, and QR codes encode different lengths of data differently.
Two rows/columns out next to the big blocks on the left, there are lines of squares that contain information on which direction the QR code is supposed to be read, and the amount of error correction (because we don't want to read error-correcting bits as data). Unfortunately, most of that area has also been blacked out so recovering the contents will be harder, such that almost all different combinations of formats and levels have to be tried.
https://en.wikipedia.org/wiki/QR_code
