I haven't been in contact with Franck for some considerable time now, so I don't know what is going on. I have searched my various computers and can't find an email though I am sure I have communicated with him in the past. However, via several websites I ended up at Au Cactusphone and found what might be an email. I've sent a message to that address, and gmail hasn't rejected it, so I am hopeful.
Of course there's been so much change in the calssification since the one used on Mammillarias.net was established. The Breslin analysis on Cochemeia is an obvious example, but there have been many others. There appears to be no immediate successor in the IOS for DR Hunt, so its likely that any list of species will be a bit more arbitrary.