From what I have read, Elmer disapproved of the Lyman version of his bullet because the front driving band was too narrow. He did however say that it was very accurate. I believe Lyman did this because they realized that Keith's design was too wide and would often jam up against the lead into the cylinder throats. I have some "real" Keith bullets that have three driving bands of the same width and they will not go into some of my .41s unless sized to .409...
There are also two "real" Keith bullets...the early design from the 1960s with the small meplat that weights 220+- grains and the later version that was designed near the end of his life that weighs 10-15 grain more and has the wider nose like the one from NOE pictured above.
The mold I have is from MP and is of the original 220 grain design.. Very accurate and expands well when made as a HP... Also have a Group Buy Lee that has the same smaller nose design but weighs 250 grain... Have been using that bullet in the .41 Special case with 8.0 grains of Unique for little over 1000 fps... When out in Idaho I shot that round out to 400 yards with great accuracy...
Bob
