You're absolutely right. So far as I know there is no one single Canto-blues CD / LP.
However, many years ago there was this HK guy by the name of Tommy Chung who released a couple of blues CDs in English. Check him out here: http://www.youtube.com/watch?v=C8hO8T_To9M
When the song follow the 12 bar blues progression, it should be considered Blues...
The songs mentioned are quite blues in nature just they really cannot capture the mood. Not even most white people like Eric Clapton or SRV. You just cannot compare any of them with the real Blues singers such as Robert Johnson, BB King, Muddy Water, Buddy Guy etc.