john deere ar all fuel?

[Barry Ayres]

hi.
i have the chance of an ar. it's priced to sell as a non runner. it's sat in a shed for the last 15 years the seller bought it drove it about a bit and put it in the shed he remembers it as smoking quite a lot. i've been to see it and it appears to have been slobbering like a worn out big diesal with oil running down the stack i'm assuming the worst but just wondering weather it could be something simple like a plugged return from the rocker cover or over full crankcase? any ideas
Is there any way to tell for sure if it is an all fuel, it has twin tanks and change over 3 way valve but i cannot see the manifold as it still has a good tin cover.
 

[Greenday]

If it has 2 tanks then it would be a all fuel