The Duke's Plaything is still uploading to Amazon, but it's already available on All Romance Ebooks if you just can't wait until later.
https://www.allromanceebooks.com/product-theduke039splaythingbookvvi-1216810-351.html
And a separate little piece of news, I am working on putting together a PRINT collection of all The Master's New Toy tales. I hope to have more info on that very soon.
**UPDATE** Here is the link for Amazon.