>>have known two people, who have Klinefelter's, who were born with one ovary and one testicle. Both produced gametes - both eggs and sperm.>>

In that case I hope their cases have been written up on PubMed, because they'd be the most incredible case studies, as well as world firsts, and the chances of you knowing them personally incredibly small, so you should buy a lottery ticket. Personally, I think you're misinformed, and that they might have had streak gonads, but such people rarely produce gametes, and it's simply not possible to produce both. So I think you're talking rubbish. But you can persuade me otherwise by pointing to the papers which will surely have been written about these people, suitably anonymised.