My grandfather purchased it from International Harvester in Memphis, but we don't know when. We suspect it is when the IH plant shut down in 1978 IIRC.
I moved it ready from MN to MS so the hard part of the move is over. I have it on some dollies right now so I can roll it around my shop.
I am not in that trade. I was a BMW mechanic for 12.5 years and now work for a steel mill. But I have always been interested in the old school machinist trade. My grandfather was a machinist for IH then went to school and became an engineer for IH. Like I said he is highly regarded in my family and by all accounts was a very smart man and a great machinist. Unfortunately I don't remember a lot about him aside from a few times in his shop catching sparks in a pill bottle and smashing things with a hammer on the anvil.
Great thread, thanks for all the advice chaps, it applies to me just as much.
I believe that the last photo is of a crotch center, used in the tailstock for cross drilling round items. I followed up on the references posted and on page 47 of the 1943 catalogue there is a very similar item.