hydraulic pump leak

I have an Allis Challmers WC tractor with a hydraulic pump that runs the bucket on the front. The hydraulic pump is belt driven from the tractor. The pump shaft that is turned by the belt and pulley has a large nut that fits over the shaft and tightens down on the pump. This large nut must have originally had some sort of way to seal around the shaft and keep the hydraulic fluid from leaking out. This is my problem. It leaks so much that even when it is not running, it will leak out all the fluid within about a day (couple gallons). And while it is running, it throws fluid all over. I have tried putting several things in the nut to squeeze down and reduce the loss, such as 'lead rope', string, 'o'rings, teflon gasket maker, etc. None of them have worked very well, and before a short time I'm back where I started. No one seems to know anything about this pump. It has a number on it: 949-2. I have asked several people around here and no one seams to know anything about it. I could just go to a totally different pump, but the pump itself does still work well. This is hard to describe with words so I hope the pictures come through.

Take the pulley and nut off. Im guessing that'd a felt seal . Uses the nut to compress the felt. May be able to just tighten the nut but if not commercial felt is still available.

I cut some felt, greased it, and put it into the nut. (Maybe I shouldn't have greased it.) Then I used the nut to compress it. It is better because it doesn't seem to be leaking when it is not running, but when it is running it is still leaking some - even after retightening the nut. I wonder how long this will last. I put 5 layers of a thick felt pad in it. Maybe this is all the better I can hope for. Does anyone recognize this hydraulic pump and can tell me about it? Thanks