Here it is on Amazon with illustrations by Boris Vallejo.) China Mieville has called the book the first example of "new weird," a genre he now owns. Gaskell worked as a journalist for a while, and continued to write fiction until 1990. According to Wikipedia, she is now a professional astrologer.
The Shiny Narrow Grin is Gaskell's vampire novel and it is soooooo 60s pubished in 1964). I have a friend, born in the 70s, who is fascinated by everything Swinging Sixties, and this is one of her favorite books. The Shiny Narrow Grin . the book is almost impossible to find. But strangely, it's up at Wattpad. (Read it here.)