I have only seen that top box once before. The guy bought it used in the late sixties. It is Snap-On. The guy would not accept my $250 offer but it was almost mint. I have the middle, no model # on it. I would value the middle at $50-75. I have seen a few different brands that look simmilar to the bottom. If it is a Snap-On, it should have embossed lettering on the front panel.
Assuming that it is all in fact Snap-On, I would say that it is from the early to mid fifties and in that condition I would pay $250-350 for it all.