I have 2 ex-breeders from MT, and I would say the key to success is to have another settled dog to help them along.
I have 4 rescues altogether, and I'd say that in each case, for them to be REALLY settled it has taken a year - but that is to the standard that other people (including Sylvia from MT) deemed them to be 'normal'.
The first one (RSPCA) was alone of course, and she just wanted to be with me, but didn't want to leave the house at first. I think she'd been dumped as she still can't cope with us in the car, and her out of it. I guess she'd been bred from too.
After a year we got Jack (MT) who was a stray. He eventually settled down when he accepted that Tia was boss, although his sight and hearing problems didn't help.
Peggy (MT) was indeed scared of the sky as she'd been in a shed for 4 years, but this was overcome by getting her to walk near walls at night (so she couldn't see the scary sky), then slowly desensitizing her by day. I had to carry her to the park, and sit with her quaking
She had her chin glued to her chest, and couldn't look you in the eye at all. She is now the most loving, cuddly little thing who loves to run, gaze into your face, fantastic recall - wonderful dog.
Bonnie loved Peggy from the moment they met, and although like a firework on the lead at first, her desire to be with Peggy overcame all that, and she was walking on a lead comfortably within 24 hours. Peggy and Bonnie still pull like demons, but I'm not bothered - their enthusiasm for life is a joy to see!!
She still shakes a little when picked up, but hardly at all now, but is terrified of scissors! Bonnie's recall is fantastic too, and she's very funny and sweet. I am using clicker to teach her things, but generally she picks it up from seeing the others.
The toilet training was slow, and we still have the occasional accident - regular outings and lots of praise is the key!
Peggy and Bonnie were 2 that Sylvia deemed to be very difficult. I work from home, so we progressed well. I don't think it would have worked so well if I was out to work more than I am, or if my kids had been small and too boisterous.
Go to visit MT and see for yourself. Like Minimoo, go and help out - it's very rewarding!!