Did you find the plug that works for the tractor?I looked closer (well, my phone did, then magnified it) and found "ket" on the connector.
Found that connector here:
http://www.ket.com/en/product/detail-information.ket?partNumber=MG610339
Mate is:
http://www.ket.com/en/product/detail-information.ket?partNumber=MG640341-5
Now to see if there is a cross reference