Eugene R. Casey, 63     PORTLAND -- Eugene R. Casey, 63, of Portland, died Nov. 20, 2007, at Gosnell Memorial Hospice House in Scarborough.     Mr. Casey was born in Rumford, the son of Rosemond and Julia Casey. He was a lifelong Maine resident, and lived in Mexico for about 15 years before moving to Portland about two years ago. He was self-employed for much of his working career, most recently in the rental housing business.     He is survived by his three children, Chris of Brunswick, Jill of Portland, and Gabe of Aruba; as well as five grandchildren.