I've had one partial set of late 19th century Milton Bradley Geometric Solids that make me think these were likely made by Milton Bradley as well and of about the same age, c. 1880s-90s. This set is missing its original box, but is almost if not entirely complete, including both the solid blocks of various geometric shapes and flat planes representing square, triangles, pentagon, etc. Great fun to configure, perfect for drawing practice, and just beautiful.
Overall very good condition. The cones show some wear to their points, the surface of the egg is a bit rough, and there are otherwise some scratches and stains here and there. No cracks, splits or repairs. One the plans there is tiny printed text on one side and hand-written (in pencil) text on the opposite side, as pictured. For reference, cones measure 3" tall.