I suspect you may need to let Web2py create an "id" field since it usually expects one (but I'm not totally sure). I would make sure you have a copy of you're DB stored somewhere safe. And then maybe go ahead and let Web2py migrate and see what happens. Tables normally have a primary key.
I guess the only other thing is setting a connection string: http://web2py.com/book/default/chapter/06#Connection-Strings Web2py expects an SQLite DB to be in the "databases" directory and named as specified in the connection string (ie, "storage.db")(I think the "welcome" app names it "storage.sqlite").
