I agree, and I'll add to that the handle proportions ... three fingers on upper handle and thumb and forefinger all on handle. Try it on super speed; not enough room.
On the right is a cast iron Kukee bar-b-q grill. (60's era) On the left is a 2 gallon Coleman water jug. (also 60's era) He has a ring so he is married. She is taking the picture. (because of his annoyed expression) He isn't hunting or he wouldn't shave. (because of the scent) He is shaving bacause he is with her. He wouldn't if he was with the guys. They are just camping. In a towed camper, that stuff is too heavy for tenting. The photo is dated Nov 66. The razor appears to be long and silver-toned. I vote: Gillette Slim Adjustable L4. She bought it for him brand-new $1.50.
And he piled up the tinder for the camp fire before his shave. I have that exact same 60's Coleman picnic jug in Aqua, it's built like a tank. Lather looks dry... maybe it's a brushless cream? I think its a slim too.
Gave me a good laugh! He's got the look "Go away woman, I'm busy" Though from the angle / height of the person taking the picture it might be his children / teen taking it. He maybe thinking "Don't break my camera"
You know, this is a challenge, and identifying a slim is not a challenge. If you zoom in and squint, the base of the handle appears to be slightly thicker than the top. The top appears to be tapered a bit, too. There also appears to be markings at the base, numbers maybe? Could it be?? (can I change my answer?)