Wow! Your post is a Godsend! I have been researching Weimar Police School marks and have assembled a database of nearly 500 Weimar police marks (less than 5% of them are from police schools). Both your C96 and holster represent unique additions to this research:
1. Your pistol is the only C96 known to me to be marked in accordance with Prussian regulations on the front grip strap. The other three in the database with "apparent" police school marks are stamped on the front of the magazine well or an unknown location. Because of this discrepancy, I have not considered them as confirmed Prussian police school marks -- yet.
2. Based on my research, I believe the holster is marked for the Polizeischule für Leibesübungen (Physical Education). Although the mark does not correspond exactly with either the 1922 or 1932 marking orders, my research has conclusively proven that "transitional" marks utilizing the format of the 1922 orders and the abbreviations of the 1932 orders were in use between 1922 and 1932. (I will be publishing this research soon in AUTOMAG and later posting it on the forums.) Yours is the only example of a mark for this organization I have found.
Taken together, I believe your pistol and holster make a strong case for the employment of C96s in the Prussian police schools in the early 1920s. Thank you very much for sharing this information.
Two requests: May we know the serial number of the pistol and whether or not there is a date on the holster?