Trying to identify these chairs.

These lovelies came to me by way of a friend and are absolutely the most comfortable chairs I have ever sat in. So I would like to try to find more of them to complete a set. Sadly, there are no markings anywhere on them except for a hand-written number on the bottom of the seat. I am fairly sure the seat vinyl is not original since the stapling seems to be less than professional and the screws used to attach the seat are obviously not original. Any help would be greatly appreciated.