Re: 50ish 7.5 hp Evinrude and pressurized fuel tank
That is a 1955 Fleetwin. On top of the block, back towards the head, you'll find a quarter size welch plug and that will have your model and serial number on it. I'm betting that it's a '55 model though, because of the aquasonic name on it. I own a '54 myself and it is identical to yours mechanically, but your paint sceme on your hood is different.