Ajedrez Moderno Modern Chess Set, 9 Squares with Prime Minister - Vintage

Description

'Modern Chess' set with 9 squares on each side and a Prime Minister. I think it is new, complete with book.
The booklet is "Mathematical Thesis of Modern Chess Including the Prime Minister" by Gabriel Vicente Maura.
The board has 9 squares per side on one side, 8 on the other so it can be played without the Prime Minister as a standard set.
Condition (I am trying to be precise since this is a collectable set):
The felt came off the bottoms of most of the pieces but were all still in the case.
There is some wrinkling of the board lamination.
The accompanying booklet has a flaw in the way two pages were cut, leaving some extra paper outside the bounds of the page.
I had to use some google-fu to figure out what this was. I doubt it was ever played because the book was completely flat.
Wikipedia has an article on it under "Modern Chess"