I don't think those are unique to Lehman. This looks like the same thing at woodcraft: http://www.woodcraft.com/Product/2000243/220/Chisel-112.aspx

Note that niether site tells you the brand name. I bought one of these from woodcraft 15 years ago as an ignorant ameteur, and it was junk - would not hold an edge. The one you want is also on the woodcraft site: Barr Framing Chisel

But you can get a better price at their own web site: Barr Framing Chisel

In my shop, we use laminated antiques. Look for a post on this forum by Jom Rogers.