HP ratings were different from the 50's up thru the late 60's to early 70's. HP was rated at the prop or the crankshaft. Sometimes a prop rated engine is changed to a crank rated engine with different HP ratings but are the same engines, just how the HP is rated.. Not sure the old 7.5 will be much faster than a newer 6 hp !! Also the old metal cases made those old motors heavier, so consider that fact.
Could be, but my old 7.5 Evinrude (1957) was way heavier than my 7.5 hp Evinrude from the late 80's !!
