I have heard this before, but I think the story I heard was that it was when Elvis and Priscilla were in Hawaii in 1968. There are photos to document the visit and since it was just a vacation rental I suppose it was possible that Elvis would have no instruments there, but to visit Graceland and have no guitars is ludicrous. Me thinks that perhaps the boy toy from Wales is getting a touch of the dementia. About as true as the time he said Elvis' range was quote, "almost as good as mine"
By the way while we are Tom Jones bashing as a woman I do not find this guy attractive at all. They say in Hawaii Elvis kept his shirt on next to Tom on the beach because he was self conscious of his skinny chest. Rest assured Elvis you were hotter!