No, you are not confused, it's all right what you suggest. I wrote in the beginning of the twins, Mathias and Mathias Victor, he had no children. Susanne was the daughter of Mathias Schnitzler, her husband Wilhelm Kuhn.
I was confused, because i read his name in the post directories after his death. But i guess you are right and Wilhelm Kuhn took over the business and used the name.
Thank you Forfarian, so no dead Mathias walk around in Edinburgh. 😅