These are my very favorite blocks. I've found two groups of them before, of slightly different whites/creams each time, and perpetually keep and eye out for them. Thje first ones I had purchased at Brimfield from a dealer with whom I talked about old blocks for a good 20 minutes--he, like me, had a lot of knowledge about early blocks, but neither of us knew the maker of these, and he'd spent a good bit of time trying to figure it out. Whatever the case, modular graphic perfection I think, and with the best green roofs.  There is slight variation to the faces of the square blocks, with one larger window/door on one of the sides, as pictured, and one plain white (cream) side on each. C. 1920s or so I believe. Not a large set, bit enough to configure in all sorts of satisfying ways, and nice to have a triangle roof for each square block. 

All blocks pictured. 6 large cubes, 6 large roofs, 1 small cube, two small roofs. Large blocks measure 2 1/8" square. There is a fun little drawing on one of this small roofs, as documented. All in good shape.