i am not an expert but that selma looks completely authentic to me. the saffiano leather looks pristine. the hardware looks good. even the sticthing looks perfectly straight. i have not seen a MK fake but i have seen other designers knock offs and you could just tell by holding it and feeling the leather/hardware ect. also the lining should be perfect and consistent with the designer and the particular bag. however if the bag feels like you could pull it apart..then its probably a fake.
Thank You !! You are very helpful! Do You think it's large model? The seller wants for it 350 USD , it's brand new.