Again, if what you have is simply the body book by Ghia, it has little value in terms of using it to do anything to your car.... The information is pretty basic, and the parts with part numbers mean only something to the factory....which is pretty much boiled into the ground at this point. A new version of these was reprinted not that long ago.
Most of these are reprints of originals.....with the "red car" cover as yours has. I forget the name of the books.....but that picture was from that particular book.
The chassis book I have is dogeared with use in contrast!! I think I've looked at my body book about three times.....and then found out I was missing pages when I had the chance to review another!
Owner's manual: It has perceived value. These were definitely reprinted.... I would expect an original to have aged around the edges from being tossed around in the glove box etc. Too clean? Probably a reprint. Check the back cover for dates??? Hall logo?
As for the manual itself, it is useless. Read it and see. It's good for telling you that you have a V8 with spark plugs of a certain type.......and that is about it. I had to laugh when I first read thru mine! No where does it tell you about the 7 switches you have on your dash or how you need to open up the entire car to turn on the heater...or off!!!
Now, where you may have value, is in the sales brochure! There are several flavors....of color versions....a 4 pager and a many more than 4 pages version! I think there is 8-12 pages in one of them with just about every color of car that DeT made. These multi page brochures are very difficult to find in super great condition and can bring some very good lira! The only other one that is very unique is the homologation report. Those are cool, but mostly in Italian! These will not tell you much about your car, but they have great old pictures and such!!! There they have great value!
Good luck on your sales!