that would be your own judgement call.personally i wouldn't be afraid to eat them.being frozen would have retarded any spoilage or bacteria growth.i'm sure lots of commercially caught fish are kept iced that long before cleaning.
Life is not a journey to the grave with the intention of arriving safely
in a pretty and well-preserved body, but rather to skid in broadside with a smoke in one hand and a beer in the other,
thoroughly used up, totally worn out, and loudly proclaiming....WOW -WHAT A RIDE!!!!