Thought I'd share some pics of the unusual A/C system in 898. The front portion that's visible looks completely normal, but the blower and manifold ducting seems to be unique. I have spoken with Bill Lavinger (owner from 70's to 90's) who has known the car since delivery and owned three Mangusta's (898 included). According to him this A/C system is factory original to the car and the only one he's ever seen or heard of.
The blower box is separate from the vent box with a splitter or manifold attached to it, from there it has a 50mm tube feeding a vent on the lower left side of the car, just under the dash below the ignition switch. The middle outlet is 60mm and feeds the normal vent box and the right outlet is another 50mm tube that feeds an underdash vent on the right side. The system was non-op when I got the car and I am having a new condenser and hoses made, have purchased new 50 & 60mm tubes and will advise as to it's effectiveness when it's all back together.
I included a shot of the inside of the glovebox to show that there is no glovebox, just a view of the ducts and manifold.