You can get all the manuals for all Picasso products from the creator's website EXCEPT this one
http://www.sophisticated-development.de/
Tobias "Mastatabs" Seiler is quiet talkative, perhaps he'll send it you if you mail him? He's also quite active on A.org (although not as much lately).
He sent me his Amiga Hardware Reference Manual 3rd Edition a few years back
