Separate serial number sequence. Yes supposition is that S,D&G placed an order w/ Georg Lindner & he made the subcontractor selections. Then in 1874 where there was a changin' of the guard, H.A. Lindner stepped into the shoes as a prime & he seemed to source from mechanics who hung out their gunmaking shingle during the same period. More than likely he was classmates w/ those with whom he sourced?