It is "interesting" for sure. As a lamination it does not look quite right. I think its all PMD, It looks as though a soft material was pressed into the coin, which made its shape distort.
Thank you, for the input. I lean towards PMD too myself but the area in question ( reverse ) is perfectly within the field and the rim is intact and undisturbed, so that makes me believe some foreign object during stamping...lol aaargh.
Since the design elements of the coin are not terribly distorted under the "lamination" area, I do not think this was PMD. If something were pressed into the coin the design would be distorted to a greater degree. Anyway, that's the way I see it.
Could be, however, the "rb" and, to be a little more precise given the "damage", the "i", may require a suspension of belief, I think.