Not exactly period photos or WW1 but still interesting to see that a student pilot of the 3rd Reich era looked alot like a WW1 pilot before turning into a Luftwaffe Flieger...
For the Military Aviation fans, here's the Luftwaffe Fliegerkopfhaube LKpS101 (Summer Flight Helmet) depicted in the 2nd PC above (helmet alas missing its connector):
Along with its Winter counterpart in mint condition, the Luftwaffe Fliegerkopfhaube LKpW101 depicted in the 3rd PC above (both helmets made by SIEMENS c1940s):
And although I try to stick to German militaria (WW1 & WW2), here are the USAAF counterparts... You will notice I'm still missing the Oxygen hoses on the 2 Luftwaffe helmets above but these cost twice as much as an entire US flying set (hose inlcuded)!!
I finally managed to get my hands on a WW2 Luftwaffe Oxygen Mask Model 10-6701 complete and in great condition. It wasn't cheap but I couldn't resist acquiring it along with a very nice Luftwaffe Summer Flight Helmet LKpN101 (depicted in the 4th postcard further up).