Your Massey Ferguson 135 tractor was manufactured in 1968. Massey Ferguson used a nine character serial number system — a number sequence followed by a three letter prefix — beginning with the MF35 in 1956 and ending with the 1085 in 1975. The first character of the nine-character sequence is a letter indicating the decade of manufacture. Your Massey Ferguson 135 serial number “9A85276” indicates a unit manufactured in 1968. The next four characters “8527” represent a specific tractor model, and the last three characters — “6” — indicate the number of the unit manufactured that year.