Gas Cap three piece need help identifying

[nova]

I found this gas cap on a mound of dirt while detecting. I was wondering what type of machinery it went to? I searched the net for another like it with no results.
the diameter 2.75" (2 3/4)

Thanks

 

[jeff of pa]

sorry , other then it's a Diesel Fuel Cap I have no idea on age.

of course the loop was for a chain so it is semi Old,
which is sort of obvious anyway

Cool Find ! I hope it's from a REO

 

[Tony in SC]

CAT backhoe, mod 420D and others. Tony

 

[petecnc]

i think tony had nailed it. the loop on the side is for a paddle lock, the other half of the loop would be attached to the fuel tank..