They are good to excellent boats for pugetsound up into the canadian waters to the north. A fairly large Jeanneau group meet at bedwell harbor the last weekend in June for a roundezvous also. Mostly newer boats, but a few Attalia's show up.
They are built like my 2' shorter Arcadia, no real ability to put a shower in, as there is no sump. Hotwater might be doable. Water capacity, probably not too hard, as teh tank is a flexable bladder under a seat. so add another bladder under another seat. I personally find that I have filled my 22 gal bladder maybe 3 times in 4 yrs if that! But then, I have not done any major week long cruises either.
Not sure about your fuel capacity, I have 7 gals, if I full throttle it I have about 7-8 hrs of use, if at 3/4 throttle, I use .5 gals an hr with a 16hp twin cyl Yanmar. The tank should be in an equal spot as mine, under the starboard cockpit seat, while a PITA to remove and put in a bigger one, not a big deal. I find it easier to carry a 5 gal jug with a non drip/pour spout, Ie one that I can put the spout in the filler, push down and fuel comes out.
Ice box will keep a couple bags of ice for 2-3 days in 70-80F temps.
Portlights? I will assume the side windows. I have had a leak or two, and got this fixed. Not sure they would be easy to R&R, but would be doable. Try to use the old ones as molds. Mine are in two pieces per side, not sure about the attalia, would assume equal.
Argle bargle on here sold/traded in his Attalia on a Hanse a few months back, you might try to see if the one you are looking at is his old one. He might be able to get you some info on it. Or if you go to Jeanneau-owners.com, there is a list of owners that self registar, see if the one has a previous/current owner to get info if it is a dealer owned rig/ ie traded in on a larger/different boat.
I believe there are clost to a dozen Attalia's in the greater puget sound area including north to BC.
marty