He got back to me, here is what he said and a pic of his tabs. Let me know what you think, thanks.
Hi Dan, be happy to answer all your questions. I bought this boat with the motor in non running condition in the fall of 2010. Turned out the oil injection pump drive gear had failed, so most of the cylinders had been scored. I rebuilt it myself, except for the cylinder boring. All cylinders were bored oversize, all new pistons and rings, all new crank bearings and wrist pin bearings, and new drive gears for oil injection pump (obviously). This is the third season I've used it and the engine has run perfectly since, and I've put 10-20 hours on it.
The hull is in good shape, it does have surface scratches and some fading, but all gel coat chips have been repaired.
The fresh water pumps work, yes, only issue is that a new shower head is needed on the stern platform. It was leaking.
I haven't checked compression lately, I'm very confident that the numbers are what they should be on a new engine.
Impeller and wear ring are in excellent shape, I've been very happy with the Mercury Jet drive. No cavitation whatsoever on this boat.
Trim tabs are hydraulic with helm controls. They are made by Bennett.
Yes, the previous owner left it out on the water without a cover, that explains the seat condition.
Everything but the shower head I mentioned is all there, the gauges work except the fuel gauge reads full when the engine is running, with ignition turned on and engine off it reads accurately. I haven't looked at why that is yet. The low fuel (20%) alarm works, as do all the lights. Radio/cd player works except for the track "back" button. Speaker grills are cracked from sun as well. Comes with a ski pole.
I have a a few photos on my phone I've attached of the trim tabs from when I installed them. I'm away this weekend till Sun afternoon, but I can take some more then if you like. Hopefully this information helps, I'm very honest about the condition of this boat, and the cosmetics are the reason I'm asking $9400 as opposed to what a "less used" 2000 Islandia is typically priced at, in spite of the "like new" engine in this boat.