Looks normal to me.
I took the top perfs to compare with the other sides. Full disclosure: a short section of the top was used and was extended against the bottom perfs by repeating and overlapping a small portion.
the perforation holes on the right side don't look to be square with those on the other three sides.
I think they are. The perfs on the right were roughly punched; note the large chip within the 4th hole from the top. Many of the holes below that are incompletely punched/not perfectly round; worn pins, maybe. The gauge/spacing is correct to me, the hardest thing to forge. With perforating wheels used, the opposite sides should be essentially parallel; the whole stamp will not necessarily be perfed absolutely square. The side perfs vs. the top and bottom are out of square by about 1.5 degrees here.
Don't expect perfectly formed round perfs on genuine stamps.