Re: Bought a pontoon. Can you identify it?
Maurell Products made Crest pontoon boats at that time. Look on the starboard - stern side, right above the toon, there should be a nameplate there. Will be stamped aluminum with the model # on it.
About your Merc 900 motor (from oldmercs.com).
The serial number was on a plate riveted to the port side of the swivel bracket.
Serial numbers 4845301 through 5160323 are 1978 models.
Serial numbers 5160324 through 5594656 are 1979 models.
Good motor for that sized pontoon. I have a Merc 1500 on mine.
Mods --- well, all sorts of mods! But I would check your transom wood first. Make sure it is the right type of wood and not rotted out. Don't want your motor to torque the wood, break it off, and send your motor to the bottom of the lake
Other mods... I would get bimini tops of you don't already. Get out of the sun / heat !