Both types are the same on the front, so the reverse photo would be definitive. The first step towards better photos is just to crop away some of the excess area around the coin. I have an iPhone and its photo app has an Edit ability. There’s an option to crop and straighten where you just drag the border of the picture where you want it.
New photograph. 1937 Buffalo. This one has a couple of nasty looking tiny spots, but overall is a lovely coin. You just don't notice the pinpoints in hand.
New photographs. 1938-D Buffaloes. The bottom one was acquired from @jtlee321, which implies that it is still worse than all the other ones he has kept. Those pictures of his other 1938-D's are amazing!
The original post said any nickel composition is OK, so here is an 1886 3-cent nickel Proof. For some reason it's not graded as a cameo. Dunno why.