I've never seen these films, but I understand that a certain adult oriented magazine published with a well known fondness of classic films is a fan and he paid to have them restored and preserved. (He also contributed heavily to the restoration of the Sherlock Holmes series.)
I read on a classic horror board that the copies selling on ebay are quite good. There is some speculation that these copies are derived from the restorations noted above.
I got a copy of "Daughter of the Dragon" from www.marscollective.com but the picture quality was mediocre. It obviously was transferred from VHS, but I guess it was still watchable.