Actually, I've made a Boo Boo there. Mercs TNT first hit the market in 1966 not 1967 as I wrote in my last post. Woops.
The motor probably had the TNT fitted at the Dealeship.
When I was a boy, my dear old Dad always said, he wished I had the same enthusiasm for my School Work, as I did for boats and outboards.
I was a real dunce at School, that's for sure.