I like the old stool - makes it seem so more amazing that the atomic era could begin way back then.
Absolutely. My memory is a tad rusty (like that stool!) but I believe I read somewhere that the accidents these guys had at Los Alamos were more related to the neutron reflectors than the actual masses of the fissile material itself. Still, playing around with that stuff on such a crude basis (with screwdrivers?) probably would have resulted in mishaps in any event.
That stool is stashed somewhere as radioactive waste!