I thought that might be who, but there is also honeybee, and dr. greyson. I am not sure what all dr. greyson does. I have only heard of his 1911 exploits.
Here is the way I look at it....
Ol'Yeller is known for his M&P work being fantastic, this doesn't rule out all of the other stuff he can do... but illustrates his M&P work is top-notch.
Dr. Barry is known for his 1911 goodness...
Honeybee is a genius for finishes, especially classic finishes.
All of them are great at other things, but from meeting each of them and spending a good amount of time with all of them (not so much 'Yeller), these seem to me to be what they really specialize and excel in.