ID a Motor

[johnh4054]

I have a older Johnson OB I Think. of corse it's white and says Johnson on the cowl, but the numbers I find on the trim aera is Model # 115593E Ser # 10007101. Now that makes it a 1975 115HP Evinrude. What gives??? may be the trim unit was changed or ??? Any Ideas, the parts should be the same but it's got me wondering what do I have??.

[boats.net]

See if can find a round plug on engine block with serial number and see if serial matches.