Very sorry... very sorry...
here is the map link combing the 1st and 3rd ages:
http://www.geocities.com/otsoandor/Bel_Eri.htm
As far as this question:
"Where does it say in those books?"
If this was asked of my referrences to "Shaping of ME", merely look inthe index. "Himiling, Hill of" has many page referrences. One of these is also to the "Island of Himring". Page 242 makes clear referrence that the two are one and the same.