What a great, complicated, seemingly old-fashioned block. It appears to me to be a variation on the Weathervane block, an example of which can be viewed here
http://www.generations-quilt-pattern...ilt-block.html and in BlockBase.
Imagine the Weathervane block as the center of a larger block, turned on point with the HSTs in the Weathervane illustration eliminated to form a five-square criss-crossed X. Add isoceles triangles to the 4 outer squares of the X, draw connecting lines from point to point of the isoceles triangles to create the square, and "fill in" with diamonds and triangles. It should be fairly straightforward to reconstruct the pattern (and crazy-making to sew!), but I can't find a name for it. I checked Blockbase and didn't recognize it. Good luck; I would love to know the name.