Dennis Quackenbush (good luck getting on that list....can take 5 years before you get lucky enough, if you get lucky enough).
http://www.quackenbushairguns.com/
Gary Barnes (the airgun version of the fantasy knife.......very long wait and VERY SPENDY!).
http://www.glbarnes.com/index2.html
There are one or two others, but the quality has either proven to be.....uhmmm.....let's say "non-existent", or has yet to be proven.
The guy producing the Gargoyle is very serious about meeting the demand.