Not sure what that might be. Only other reeds I know of being used are Voci Armoniche, which I don't care for, and Antonelli.
You won't find old Hohner or old German made reeds except by pure luck. If you're wanting mellower, the Harmonikas reeds are definitely mellower. They have several options, I've tried 3 different versions of their reeds, all different sounding. Never tried higher than D, though.
I stumbled on a pre-Hohner German accordion made by Koch, probably early 1920s. 3-row box, F, B-flat, E-flat, two reeds per note. I didn't think about repurposing the reeds, but this thread has me thinking. Link #1 is an overview of the instrument by a local repair tech who restored it, Link #2 is his shop, Link #3 is Scott's YouTube page. He teaches engineering, and has an amazing setup for repairs.