Artist Ahead music publishers are offering all 3 volumes of Steve's highly regarded Blues Harmonica Playalongs series as downloads (mp3 audio file plus pdf text/sheet music file). They are available either as complete book/CDs or as individual titles:

Complete book/CDs:
http://s296368176.online.de/shop/index.php?cat=c152_complete-works-english.html&XTCsid=4dfee8dccfdf7ceb4dbcb04b6168b65e

Individual titles:
http://s296368176.online.de/shop/index.php?cat=c148_-nbsp-Steve-Baker-Playalongs.html&XTCsid=4dfee8dccfdf7ceb4dbcb04b6168b65e