i am intrested in purchasing a seiko 6309 704X diver. it looks like the bay is the best place to find them. my concern is some of thier authenticities(sp?). does any one have any good advice on how to spot a quality, worth while 6309? also, i notice that some of the winding rotors just say "SEIKO", while others say "SEIKO TIME CORP: UNADJUSTED". are they both genuine 6309 movements? any incite would be helpful. thanks.