As I was looking at old shaving videos, I came across memory.loc.gov which had several vintage shaving images, including these great photos of servicemen shaving:
GI shaving in foxhole using helmet as basin (1945)
Soldier shaving (date & location unknown)
Fifth Cavalry in camp at Grant Park in the Loop community area of Chicago, Illinois (1915)
Fort Belvoir, Virginia. Sergeant George Camblair shaving in the morning at the camp. (1942)
Sergeant Crowley holding a mirror and shaving, kneeling in a field (1927)
GI shaving in the shell-blasted church at Pietra Colora (1945)
Recruit lathering his face with a shaving brush in front of a makeshift vanity at the military school at Fort Sheridan, Illinois (1915)
Recruit shaving at a makeshift vanity at the military camp at Fort Sheridan, Illinois] (1915)
Italian boys watching a GI getting a shave (1945)
GI shaving in foxhole using helmet as basin (1945)
Soldier shaving (date & location unknown)
Fifth Cavalry in camp at Grant Park in the Loop community area of Chicago, Illinois (1915)
Fort Belvoir, Virginia. Sergeant George Camblair shaving in the morning at the camp. (1942)
Sergeant Crowley holding a mirror and shaving, kneeling in a field (1927)
GI shaving in the shell-blasted church at Pietra Colora (1945)
Recruit lathering his face with a shaving brush in front of a makeshift vanity at the military school at Fort Sheridan, Illinois (1915)
Recruit shaving at a makeshift vanity at the military camp at Fort Sheridan, Illinois] (1915)
Italian boys watching a GI getting a shave (1945)