In my meanderings at a used book store, I came across Dale Estey's books "A Lost Tale," (see link below). It was published in 1980 (not 1955 like Amazon says). The book takes place on the Isle of Man during WWII, and Celtic mythology comes into play. I opened it the night I bought it, thinking I'd read a few pages and go to sleep. Next thing I knew I was 70 pages in. A real hidden gem.
Amazon.com: A Lost Tale (9780425071335): Dale Estey: Books
Amazon.com: A Lost Tale (9780425071335): Dale Estey: Books