This is a very interesting gun for those of us that appreciate German combination guns. I have seen similar guns pictured or written up in articles but based on mod. 98 Mauser actions, not mod.88 Commission actions. I doubt that it was actually made by Nimrod Gewehr Fabrik.
Rather, I think (without proof) that it was likely made by another craftsman for marketing by Nimrod. I believe a "Schlegelmilch" was associated with Thieme in Nimrod, but it is spelled "Schlegelmich" in the advert. It is well known that Louis Schlegelmilch in the Spandau Arsenal was the "daddy" of the Mod.88 bolt and Nimrod would not likely misspell the name (even if they are different people). As I indicated, this is only one person's opinion.
Mike