Rooting through my change from going out on Friday I noticed another 'greaser' to add to my pile. Nothing earth shattering, but a pleasant surprise, none the less.
I’m going to disagree. Die adjustment strikes would be more uniform on the coin, with the outside showing less and the devices in the center showing more. The flattened area wouldn’t blend so much with both devices and fields. This looks like a really nice greaser.
I’m just having a hard time with equal amounts of grease on two dies in the same area at the same time. If a die was being adjusted it could have been tighten except in one area. I have a die adjustment strike coin but no photos. White it is uniform it has areas that show more details and the center is missing as much detail ss the outer edges. I’m just not sure but stating a different possibility.
If the coin were underweight, it could be a possibility. https://www.error-ref.com/tapered-planchets/ I understand your concerns, but here’s some reading with photos that might help support my suggestion: https://www.error-ref.com/struck-through-smooth-viscous-material-grease-oil/
I weighed the coin multiple times: 2.500g., 2.498g. & 2.500g. The diameter is within specs also, 19mm.
Everything I see says struck thru (likely grease). I’ll see if others have a different/better explanation.