I'll take a stab....Linden-Koshollek?
Yes. Well done.
It is stocked by Alvin Linden. Beyond the bolt knob, likely not a lot of Emil Koshollek work. Linden made his own barrel bands, and there isn't a lot of metal work beyond that.
Linden mentioned his "Sibley checked" butts in his stocking pamphlets, but died before writing the checkering book for Samworth......so there isn't any instructions for it. My rifle is the only example I've ever seen. I've heard that many examples of his checkered butts were replaced with pads or metal buttplates. In truth, it probably is a bit impractical for a hunting piece. The fact that this is a target rifle, and was used as such by the man who owned it, probably is the reason it still exists unchanged. It's an interesting exercise, because it's checkered horizontally, vertically, and diagonally. Under magnification the points appear like pyramids on a square base.
The man who inherited the rifle from its original owner also knew Linden. He would have been 39 when Linden died. I regret not pumping him for more information, but I had just begun my own familiarization with Linden's work. That started when I took possession of Emil Koshollek's personal hunting rifle. That verified by a nephew of Emil's. My brother, Idared on this forum, now owns that rifle.