Hmm... that's not a microscope, but a microscope illuminator. The tube is not meant to be pulled out; it fits down in the fixture with the round hole facing the lens. The spaces in the top of the tube are to let the hot air out.
The illuminator is meant to be aimed at the mirror on a microscope. From the looks of it I would guess it was made in the 1940s or 50s.
The bulb is just what it says and is probably of no particular collectible interest, unless you want that model of illuminator to match up with its contemporary microscope. You might search on the Web for microscope collectors.
My 2 cents,
Chris