The rifle you refer to is now in the collection of the Museum of the Fur Trade and was on exhibit when I last visited the museum about 18 months ago. It is also pictured in the book, GREAT GUN MAKERS OF THE EARLY WEST Vol III, by James D. Gordon on page 385.
Gorgon's book has full colored pictures of 35 Hawken rifles by both J&S and Sam including half-stocks and full-stocks, mountain rifles, target rifles, and small caliber sporting rifles. The book has pictures of four Hawken pistols and a number of rifles built by individuals associated with the Hawken shop such as W. S. Hawken, and Hoffman & Campbell. Most of the Hawken rifles are from Gordon's collection, but also from the Museum of the Fur Trade, the Buffalo Bill Historical Center, and several private collections. I haven't bothered to count them, but many of the rifles pictured in Baird's books are included in Gordon's book.
If you are interested in Hawken rifles as well as trade guns and trade rifles that were common in the fur trade and the West, I highly suggest you get a copy of this three volume set. It is pricey at $295, but well worth it for the serious student. You can order it directly from James Gordon or through the Museum of the Fur Trade. Another option would be to try to get you local library to purchase a set for their collection.
An interesting detail shown in Gordon's book is that the breech plug still exhibits a blue hue from the color case hardening,
I believe one could build a reasonably close replica of this rifle based on the description in Baird's book and pictures in Gordon's book. You could get by with either shortening one of the straight taper barrels available from several barrel makers or using a straight 1-1/8" barrel, since the 1/16" taper on the 29-9/16" barrel would hardly be noticeable.
The lock, as pictured in Gordon's close-up, resembles the old Cherry Corners lock, especially the hammer, more than the Ron Long designed lock available from R. E. Davis. The hammer style on the old L&R Hawken lock would work, also. I don't think the new hammer style on the L&R locks is correct for any Hawken.
Your choice of breech plug is probably limited to the styles of TOTW's #Plug-JB-18-3 or #Plug-JBX-18-3, since it would need to be 1-1/8".
For trigger guard, definitely use TOTW's #TG-Hawk-H-I. This is the only proper trigger guard for a Sam Hawken rifle.
You may want to make your own two-piece nose cap like the original or modify TOTW's #FC-SH-16-1 for a 1-1/16" barrel and notch the front edge.
TOTW's #BP-Hawk-L-I butt plate most resembles the pictures in Gordon's book, though the original appears to have more curve in the crescent to me.
Other small details such as the fatter oval shaped barrel wedge escutcheons, broad head shaped finial on the toe plate, and short tear drop shaped lock bolt inlay are evident in the pictures in Gordon's book and would be easy to copy.
Good luck with the project.
