I know this car and the seller personally, and can vouch for the quality and condition of the car, and the seller as a true enthusiast. The prior owner is a highly respected air-cooled Porsche specialist, and has been my long-time mechanic / consultant on everything I've owned from my first 3.2, to my RS America, 993, 996 GT3, 997 GT3, 997 GT3RS, GT4, etc. Rest-assured you will not find a more properly sorted and uniquely spec'd M505 out there. Bid with confidence and GLWA !
Also @edinphx - The high and low hoses in the engine bay for the AC are deleted, but it's very unlikely they removed the balance of the system. The remaining lines, condenser, dryer, blower, etc., are all buried pretty far in the driver's side and front "suitcase" of the car. Seller could confirm by peeking behind driver's side front fender liner / removing suitcase plastic cover in frunk. Likely very easy to add back. As is the catalytic converter, albeit expensive new. Plenty of used parts out there.