Nice discovery, Crane Driver. It immediately struck fire in my poor little brain and I looked in the Oxford English Dictionary. The definition is "the sailors' Elyseum, in which wine, women and song figure prominently."
The first quote is from 1805: "My grannan....used to tell me that animals, when they departed this life, were destined to be fixed in Fiddlers Green." 1836: "It is believed that tailors and musicians after death were cantonned in a place called Fiddler's Green." 1837: "We shape a course for Fiddler's Green" (Marryat). 1883, Kelly: "The pilotless narrows, which lead to Fiddler's Green, where all good sailors go."
The origin would have to be at least 18th C. Not only sailors, but animals, tailors and musicians (just Mudcat musicians or all? Rappers and Heavy Metal as well?) go there. Members of the US Cavalry go there.
It must be a crowded place.