The serial is found on the aluminum plate on the front between the transom mount brackets. Those decals look a lot like the one's on my 1975 Merc. My '72 has a brown stripe.
ya the boat is a 76 glassmaster so im most likely looking at a 76 or 75 i suppose the metal is worn away i already treid that. it still runs ok too id like to sell for 500-750 hopefully