So to get anywhere near what the original Master Tape sounded like you need first pressings and then there would be some variation between the first thousand pressings and then onwards with a gradual decline in quality as the stampers wear out.

Determining the providence of any of the Master Tapes used at any point in time by any production company re issuing is never mentioned and probably only known by a few as I presume there must be some sequential number used to determine first, second, third generation. etc.