As I said before, this "Plains", "Hawkin" and "Lehman" rifle builds are very confusing!!!
I have a semi cut half stock with a beavertail cheek piece, but it looks mis-drilled and off center.
Regards;
Ray Pennington
Ray, these terms have become confusing because they have become generic, like Saran Wrap or Xerox copies. If we keep using them as generic terms, the confusion never abates.
A Hawken rifle is a rifle made by a member of the Hawken family or out of the Hawken shop. Jacob, Sam, etc. Real men with the last name Hawken. They made a wide variety of rifles over a long period of time to meet a variety of needs. Early rifles Sam made before he came to St. Louis are fine flintlock longrifles, brass mounted, "Golden Age" longrifles. While in St. Louis, the local small game rifles and the rifles for the west, known as plains rifles or Rocky Mountain rifles, were their major outputs. People have spent their lives researching the nuances of styles of Hawken rifles. For the person who has a barrel and wants to build a gun of the percussion era around it, the question is, which style of gun appeals to them and fits the barrel.
There are a number of good books on Hawken rifles and on Plains rifles, and a lot of information on Lehman rifles. The worst sources of information are catalogues from suppliers who offer scores of kits.
Lehman rifles are rifles made by gun works run by a fella named Lehman. In general these were cheaper rifles made in very large numbers. Some of the ones the kit makers offer are based on very late guns from the 1850s or even later.
Plains rifles or Rocky Mountain rifles are commonly thought of as large caliber, strongly built, often half stock rifles with double set triggers made for the western trade, for the mountain man. Jacob, Jacob and Sam, and later, Sam Hawken were among the many suppliers of plains rifles and their rifles were considered high end and have become legendary. There were makers all over, from the east to the upper Midwest, who supplied Plains rifles for the western trade.
If your interest is in building a rifle around your barrel, and not in learning all that is known about the rifles made for the western trade, it's best to decide whether you want a rifle that is based on specific originals or not. A generic plains rifle may be just fine with you, or you may be the type of guy who wants a "Bridger" Hawken, which would be a copy of a specific Hawken rifle owned by Jim Bridger. It's possible to copy many different specific rifles made by J&S or Sam Hawken. Or it's possible to study enough of them to put together a Hawken rifle that is representative of a particular time in their production.
It's just as legit but not as popular to build a plains rifle that is not a Hawken rifle. This could be a copy of a rifle made by another maker, or something generic for the western trade.
Take your time, learn as much as you can or need to, then build something that appeals to you.