all i can tell you is this,
transom cracks crappy wood pull always in the corners, look for a water line in the bilge means its holding water in the winter or taking water in season, look at the bottom of the motors check the skeg and lower unit for cracks or malformed, take the plug out of the bottom of both motors check the oil if its milky do this after you have had it running and put power to the gear box, bad seals and improper winterization , a compression test is good but you need a baseline number you can run this pretty quick with a cell phone and a serial number, enquire about the current owners winterization process. pull a plug two strokes are pretty reliable if looked after, pull the cowls off the motors and look for excessive hydrocarbon residue on the motor and low spots. and last but no least check every single electrical connection make sure it all works and get a set of bunny ears and run both motors not just for 5 minutes leave it running for at least 15 cycle the gearbox and increase the rpms. dont go in all excited if they see you do all this it gives you wiggle room on price play poker!
nothing worse then separating from good money and nothing better then a good day in a reliable boat!!!!!!!
Happy Fishing