Wendy - Thank you so very much for taking the time to check out the monkeys. I will take your advice and contact Skinner, however, can you provide the sites/books where you found similar pieces? And were any of them by a particular artist? I'd like to think they would cover the mortgage if we sold them, but, truth is, we bought them at a yard sale because they "called to me" and I have come to love them dearly, especially when they run loose in the house at night (cats hate 'em).
Again, thanks so much and I will let you know if I find any details about provenance. And thanks also to all who commented. This is a terrific site!