I found a map from 1700 that spelled it Ambergreef K.
but the map maker misspelled a lot of things
I think its amber gris to most like your saying, "this gris amber gris.
Its the excrement of an infirm whale, an accumulation of things he couldn't digest and vomited up as a rosegrayish watermelon sized lump of 'amber gris'that floats and washed up ashore here enough to get the name when there where wales.
thats my story and i'm sticking to it