Here is my latest find from the magical world of Ebay. Just purchased this humongous prairie boot from Irish Setter. It is a size 20D, standing 26cm tall and 40 cm long. It looks completely different because of the dimensions. To compare: my size 10D is 23 cm high and 32 cm long.
From the pictures alone I would say the boots are made from Oro-Russet Portage leather, but it might be Oro-iginal. It is hard to tell though. It was originally used by shops as display material. A big boot always makes a good impression. Sorry for the bad pictures. They came straight off Ebay.