this is great. i looked recently for the same type of materials. when i talked to oliver at tab funkenwerk, he said that he is now stamping his own UI30 lams because he was unable to get them, at least in the exact material he wants. i didn't have much luck either, but i didn't find marchandise.
magnetic metals here in the states has bought up some of the other lam manufacturers.
cinemag makes some dual bobbin designs, perhaps on DU124 lams? some version of the marinair 10468 is still being made by carnhill; that's a dual bobbin unit also. and of course everything lundahl makes is dual bobbin, some laminated cores, some wound.
ed