Nothing online, actually not much in books worth a damn, but Wacker-Görtz did a book on Imperial German acceptance, it is in German of course, titled "Handbuch Deutscher Waffenstempel".
Of course it is more involved than what you seek but it is a handy book. A more practical source for you might be Proofs & Inspection Marks published in Gun Collectors Digest 5th Edition. It is a very useful, if outdated, article on the practical side of acceptance & proofing (even today most collectors that know better misuse the two words, as though they are interchangeable...)
Anyway, no one other than myself is bored enough to track or define acceptance patterns on German rifles...
Post some pictures once you get organized.