What brand of make/model disk do I have ?

[CJD55]

I have a disk about 12 ft. wide and green in color (under all that dirt). see attached pictures. I am guessing it is either an Oliver disk or John Deere disk. How can I know for sure what make/model it is?
thanks

 

[Doughknob]

give it a bath; find markings. i will guess Oliver.