You can get the print version of Tarsnap Mastery from Amazon.com and Amazon.co.uk. Other Amazon sites will have it shortly.
In about 6 weeks the book will percolate through the Ingram catalog, which means that sites like Powells and B&N will have it.
Happy owner of both print and ebook!
I haven’t finished either book but I’ve already learnt that different keys can do different things!