I think he fell off 
But really, my wife had "better things" to do than take a video of another tractor, so I had to

Yes, it had about two gallons of 20-30 year old Kerosene and this was what had settled to the bottom of that. Tank actually looks pretty good inside after a quick clean, it was all loose.
Thats lucky, rusty fuel tanks are a PITA. I remember a friend brought a Trumph motorcycle tank to me "just a tiny leak" he said, by the time all the paint and filler was off the bottom it was like a rusty cobweb. When i cut out the rusty bottom it had been 'sealed' over the top of 1/4 inch of wet rust... horrible
Do you collect vintage machinery aswell as steam engines Nick? Love to see some pictures if you get time

Ade