mezcal;280979 wrote: Not quite accurate.
Grey books (which are still green), come in many different levels of legitimacy. The most common being a book from an older bike of the same or different model. The numbers on the bike's frame and engine are then restamped to match the numbers in the book. The book itself will be 100% legal, therefore transferable onto a new owner and you can pay tax and insurance like usual. The act of restamping the numbers on the bike is obviously not legal and might or might not get you in trouble.
99.9% of all SR with green books are like that. If you can find one with a 100% legal book, you'll have to pay more than double what you would pay for a grey book. (SR with grey book~about 90.000)
When buying a bike with grey book just make sure that the bike's details match the one's in the book, i.e. number of cylinders, cc's, brand and model etc, and that the tax has always been paid.