If there is any doubt with these Sharjah dealers then why bother at all?
if you could potentially purchase a stolen bike with fake papers or a badly repaired written off bike, it why even bother entertaining them. If the demand stops then so does the supply of dodgy bikes in the country.
Having previously purchased a car which turned out to be stolen (restamped chassis number, fake papers, and cloned) believe me its no end of grief.