In general Mauser in Oberndorf made everything however Rigby in London did add a little crosspin to eleminate the 2stage funktion of the Mauser standard single triggers. This Rigby thing were suppose to activate by direct engagement of the trigger= better accuracy.( Rigby theory).
I have original sportingrifles from Oberndorf aswell as Rigbymausers. I don`t seem to notice any significance in accuracy. The best triggers today I believe for the Mauser M98 is from Recknagel or ManFred Alberts. I have mauser custom made rifles made up with both kind of triggers and they both work very well and seem to be very crips compared to the originals. I also have a B-mauser with set-trigger which is imho. hard to beat by any other riflebrand by that time of period.