You're talking about Leopold Ancion. He was a Belgian arms maker located in Liege.
I believe that after his death the company became Ancion-Marx. They continued to build sporting arms at least until 1940.
About the turn of the last century, Ancion-Marx, Alfred Franck (ALFA) and Francis Bannerman formed an international consortium and sold thousands of surplus military arms worldwide. According to Edwards, they were still selling antique arms at least up till 1961. (The book was written in 1962).
If you type "Ancion-Marx" in your web browser, you will find several sites that may have what you're looking for. I only looked at a few.
Hope this will help.
