This is a great discussion.
I found something that may be of interest while browsing through digitized back issues of
Muzzle Blasts, which are accessible through the NMLRA website. This article, by James Serven, was in the May 1945 issue:


Of particular note is the J&S Hawken fullstock, the top rifle in that group of three:

We wonder if this might be the original “Kollar Hawken,” before Dr. Kollar acquired it. The barrel is described as 38.25” long, in .50 caliber, it has a “Warranted” lock, and it has a grease hole. Unfortunately, Mr. Serven didn’t divulge much beyond what you see in the caption for that photo. I assume it was in his collection, but I don’t know that, and in the several articles Mr. Serven published about Hawken rifles, this is the only one I remember that shows this particular rifle. I understand he wrote a Hawken article for
The American Rifleman some time in the forties, but I have been unable to locate it, and I don’t know whether this rifle was shown in that article or not.
Anyway, I’m wondering if this rifle might be that original that was destroyed in the fire. A lot of the specs are similar, and there can’t be very many Hawkens with grease holes.
Notchy Bob