I initiated a purchase on a PT 35 here on the west coast last year. Love the layout.
It had twin N/A Perkins. 6 - 7knot cruise, 8 tops for that boat. Alas, way too many issues and I bowed out mid survey. Some of the issues I should have caught during my own showing. But the used car salesman style broker was very distracting and rushed me. Shame on me.
Very typical of Taiwanese trawlers of the era, so yes examine the areas around the windows. May just be condensation staining. May be secondary to window leaks. Fortunately the ones I've seen don't have exterior teak decks.
Obviously she's a SD design, and with enough HP, should get up on a plane. Those numbers sound a bit optimistic though. If you're happy even if the speeds are a couple knots slower than advertsed, go give her a good look. Ultimately the sea trial will tell the truth.
Pineapple Girl on here has one. Not sure which motors. Maybe she'll chime in. If not send her a PM