i recieved this horse for christmas. the guy my parents bought the tractor from said it was a 1961. can anyone help? the motor is a techy pull start but looks to be only a 3.5hp, a 1961 should have a 5hp. also if it is a 1961 551 should it have the key switch? i guess i'm looking for any info you all can throw my way. here is a picture of what i got.