Pontoon Boat & Deck Boat Forum

Give Pelican Marine a call. They are located in Hudson which isn't too far from you. They have a full service center and probably do pre-purchase inspection. If not maybe they can refer you to someone who does. http://www.pelicanmarinecenter.com/index.htm

If you are going to drop some serious coin on this, say over $10k, I recommend hring a Marine Surveyor. while getting a local boat mech to check it out is a good idea, insurance companies put a lot more fdaith into a surveyor's report. The fee should be pretty small for a toon, unless you get into engine oil analysis or ultrasonic gauging on the pontoons. Both would be extras based on finding something that indicated it was necessary.
Surveyors also charge for travel - watch for that! No matter what they tell you, their fees ARE negotiable!