I'd agree with Yokozuna. An over polished die and showing weak details around the head and neck on the 1975D called "skinny".
You could check it's weight o. A scale and thickness on a caliper, see if it weighs different or is thinner than the other 1975D, that could also be a cause for a weaker strike, but my money would be on a overpolished die causing it if I had to bet.
Visually if it were a slightly thinner planchet it might not be perceptible to the eye but still measurable through weight and thickness measuments.
You could check it's weight o. A scale and thickness on a caliper, see if it weighs different or is thinner than the other 1975D, that could also be a cause for a weaker strike, but my money would be on a overpolished die causing it if I had to bet.
Visually if it were a slightly thinner planchet it might not be perceptible to the eye but still measurable through weight and thickness measuments.





















