This is a real nice original Zenith 9636 carburetor for an Allis Chalmers RC, B, or C tractor.  It may also have other applications including some power units so please do your homework to be sure it fits your application.  There are no cracks, breaks, or repairs of any kind that I can see or know of.  Both shafts are stuck an it's a bit crusty so it is a project or core carburetor.  It mounts with two holes 2 1/4 inches apart on center.  The hole where it mounts is 1 inch in diameter and the intake hole is 1 1/4 inches in diameter.  These original carburetors are pretty tough to find in the wild or even at swap meets so if you've been looking for one for one here's a good, rebuildable core.  Let the pictures be your guide.  I can always be reached at 262 573 193 1 if you'd like to talk about it.  Good Luck.