My guess would be #1 a plain Jane FMJ, #2 & 4 are tracers (white and green) #3,5,7 AP's. But not sure why the different shaped steel inserts. # 6 I would guess phosphorus.The last one would be an exploding round. I know they had 20mm and 30mm exploding rounds for aircraft armament, but not sure of the 7.92 rounds ??????? These are total guesses on my part.
Good luck on your research. I know I'm interested in this one along with the K98 bayonets thread!!! Your on a roll Jersey and you have me waiting to find out answers.