Ok, So that is a compact tractor, however it is an earlier 928 Series 1, that was painted greeny/yellow and brown, and had the little blade lever. Someone has "restored" it at some point and put later stickers on it and made huge rear mudguards for it. I have one identical and it is from 1976. That engine is not original and is from 1995. Would have had a 10hp white briggs in it, going by the wider tyres.
The engine to rear drive pulley belt is a B64, and the deck belt is a B50.
There was a rudimentary brake on them, operated on the big rear drive sprocket, but did not really work and was mostly pulled off, mine has been also. I do have pictures of the genuine setup and I can see why it was a problem. Brakes are not really necessary on a cox as like a greenfield you just use reverse to slow you down.
as for the oil issue, it could be as simple as a bad PCV valve, (which is built into the tappet cover, behind the carby) or as severe as shot rings causing huge blow by pushing the oil out the breather.
