I sadly got 5 holder 10x~15mm x 4mm thickness for 9x12 no markings or brands perfect condition, I guess there is someone producing them now, they are like new :/.
If only they could fit my Voigtländer Arvus which takes the filmholders with 2mm thickness on the edges! (why not trade them )
Anyone got more info in general?
I also found this catalog, German tho: