Cory - I may be mistaken but I had a conversation with them at one time and I believe they said it is loosely based on the Klette rifle but maybe with some Hershel influence(?)
Tip Curtis sells a similar pattern I believe.
The "step" on many of these was very subtle - lots of guys go overboard here and make them too drastic. There is actually enough wood on a number of the basic early type stock patterns to add a step. You just want to make sure the comb is not cut too far back. The wrist areas tend to be fairly compact looking on these type guns and when you look at these guns from the side, they generally appear like the wrist is actually starting to flare out in height as you move toward the comb, if that makes sense, due to the visual effect of the increasing stock height.
Good luck
Guy