For a German your English writing skills are well within the Dutch standards
(every dutch person gets schooled in at least 4 languages so i think we can set a certain standard
).
On topic than, i think my earlier post has been overlooked?
If there is any room for such a study i would be more than happy to go trough my books to compile a photografical time scale on the early pistol butstock/handgrips. The earlier ones will be trick since i have limited information on them, but with some help we might be able to create something decent