Hi Vic..!
I agree with Tom that bring back papers are a terrific addition to any Luger, or bring back weapon/holster. To your question of how many there are - hmmm - that's a great question! I'm guessing in the 1950-1970s, they probably were passed over by many firearms dealers and shooters, as Luger were mostly "shooters" and were rather inexpensive.
Over the past 25+ years, as all Luger variations have become more "collector" firearms then "shooters", the verified papers have become increasingly important and, a bonus. Ergo - the increase in the counterfeit papers over the past few years - to the point, I think you could purchase "blank" forms on e-Bay a while back (someone posted that in these Forums, I believe - or the Colt Collectors Forum?)..???!!!
Anyway - please DO POST PICS!!! It would be GREAT to have a look at your THREE (!!!
) new Lugers!!!