OMEGA Speedmaster 3520.53 MK40 possible purchase, PLEASE AUTHENTICATE

Can anyone with a working knowledge of these watches please authenticate it for me? It is sold by 1 of 2 highly recommended ebay sellers that I have heard about on these forums. I would like to pull the trigger in the next day or two and feel it is a fair price for the watch, which seems on all accounts to be genuine. The only issue it has is that the authentication card is not included with it, and the red timer hand is stopped at the 1 mark?

Much appreciated in advance!

Gino

G0070 Omega Speedmaster Chronograph Triple Calender MK40 Cosmos Am PM 3520 53 | eBay