Triffid
Deeply Rooted
Nothing from this site. I only stumbled across it the other day. But if you go to the homepage there is an email link to Martin Škoberne, the admin.Have you acquired any of these varieties from the website you found? There doesn't seem to be any contact information though.
Aside from Oude Sloveense Boterboon, which were sent to me by Guy Dirix, the few Slovenian beans I do have were shared by a dear seed-saving friend who acquired them from Bohnen Atlas - the black-seeded Mazlenk Rumen Visok II and Mazlenk Visok Dolgi Stroki, which has chestnut brown seeds. Incidentally, these three are all flat wax beans, and their original native names seem to have been lost along the way (?) The current titles are rather generic: 'old Slovenian butterbean'; 'Tall butter long pod'; 'Tall yellow butter II'...