Ole, are any of your 9x12 holders branded "Contessa Nettel"? If so I'd love to have them. I think they may be the same as Fotokor 9x12, but I've never tried those. If you have any Fotokor holders, I suppose I'd like to try those too. I have only 5 holders for my Contessa Nettel Tessco now, so I'm anxious to get hold of a few more.
By the way, when I say "have them", I do mean "pay for them" of course.
I've attached some pics to guide you!