Perhaps the limited comments are partly due to the rifle being unsigned, a detraction for many major collectors when guesswork becomes involved... and auctions/sellers want to assign a quick name/attribution, so the gun has some "roots" to strengthen its value. The gun may well be a Gross, but Jim perhaps said it best when he left it open to a family member. The gun has a number of small deviations from Alfred's work in triggers, tang, butt plate heel length, very sharp comb, etc. Perhaps being mounted in German silver with a commercial guard impacted other decisions on the gun, but we're all guessing. Some of the work of Jacob Gross looks, in my opinion, closer to this rifle than Alfred's work. I think, as Jim suggested, the attribution needs to cast a wider net than just Alfred Gross at this time, until more study is done.
Shelby Gallien