Earliest Incoming Shanghai Dollar Dater....

Can I have some opinions please on this cover?, I bought it a long time ago as the earliest incoming Shanghai Dollar dater.... Also can anyone challenge this date?

Sorry but I am not a Chinese expert, but anytime someone makes a claim to a cover being "the earliest" I cringe. Perhaps in that seller's personal experience they have not seen anything earlier but given that the vast majority of philatelic material is tucked away in collectors' and dealers' stocks and even more is sitting un-noticed in attics and basements around the world the term "the earliest" has no real meaning other than to separate money from a potential buyer's wallet. Unless there is a documented proof that such a cancelation device was first used on a particular date and this is one of perhaps many that was canceled on that proven date, the best anyone can do is say the "earlist known so far" and even that would take quite a bit of research from all of the specialist collectors and dealers and societies in this specific kind of postal history.