i'm a staunch slab defender but that one doesn't seem right to me, a lot of the high points showing wear along with most of Britannia showing wear and even missing most of her hair and pretty much no face showing?
if i saw this one raw i would put it low MS? some defence for it is the fields show little/no damage and the rim looks good, also some good colour to it too which is pretty rare on a non proof for these.
I fully agree with you though, this one looks about as over graded as JB's usual listings