I did find the serial number and it is 88242-8731 and the spec number is 48-0030 so after checking then numbers it is a 1960.   I am still wondering if the fiberglass grill is the orginal.    I have seen pictures of 770s with this type of grill.   The engine is gasoline.   I will try Korves tomorrow.  I hate to part it out as I have a 1947 Oliver 88 and a 1949 Oliver 66.