I need to find the right steel for the mast and boom, and the right bearings for the base hinge and pivot. I really don't care if it ends up weighing 900lbs, so my options are open. I suppose if I wanted to be ugly I could just use greased solid steel bars as hinge pins and a greased pipe-over-shaft as the pivot. Drill a couple holes for large pins at the down and vertical position on the mast, and another to pin the pivot or let it swing.
Mount the winch on the mast or the floor, and put a moveable pully-point on the boom. Or the whole winch could be on the boom, although I don't see any advantage to that.
I would be too heavy to stand up manually, and loaded would be dangerous or impossible to swing, so there will have to be a ram. A pretty stout one...