Sounds like it is worn out and sat too long. In the 20 years I have been working on these no amount of snake oil will fix a smoker. I have had the best runners be easy to start and mosquito killers. You can try to work the hell out of it but it will probably not change much.
When you had the head off was the time to check the rings, pistons and cylinder bore. Oversize pistons and rings are a bit hard to find for unstyled tractors. The last B I rebuilt was my 39. It got 100% NOS block pistons and rings. Machine shops couldn't fix the block and mid B pistons are unobtainable at .45 or.90. It wound up being cheaper to go NOS in the end.
It may have crossed your mind...No, late b/50 pistons will not fit in an unstyled with a simple bore. The rods, pins etc are all diffrent....and there is not enough meat in the block to bore it out.
You can leave it as is and deal with the oil or be prepared to lay down 1200 to 1500 in new parts.