hello, i just got a 60's to 70's 9.5hp johnson seahorse. i can't find the model number to save my life. the s/n is j3581875. i'm looking for the year of the motor. there's a few diiferent number combos throughout the motor, but none match anything i see online. any help would be appreciated. i also have an 1986 evenrude 90hp that i want to know exactly what it takes to eliminate the vro. thank you much!