I recently added this 1 Peso note from La Provincia de Buenos Aryes to my collection - it is my first square note. Please post any non-rectangular notes, I am sure there are plenty out there?!
Here’s one of mine. A 15 Shillings Note dated October 1, 1773. It is a Colonial Note that was issued in Pennsylvania.
The name changed in 1863 from Ayres to Aires but the name on the notes took a while to catch up! and I can't spell either
This time a 'non-quite' non-rectangular note from Uruguay. The wavy edge seems to have been quite common.