Question about customs w/licensed features.

[OwenM]

I don't know much about custom knives, and have only been looking at them for a short time. Seems the reasonable route to go considering that I find most production knives have some features I want, but are usually lacking in one area or another-whether it be blade, lock, materials, or whatever.
Are custom makers allowed to make knives with features that are licensed by a manufacturer without that manufacturer's approval?
Say I wanted a custom folder that mimicked the handle and blade design of an Emerson Commander (including the Wave), with a Rolling or Axis Lock, and a Spyderhole in leiu of a thumbdisc, and maybe one of the "high speed" steels (the combination of which would make all right with the world, IMO)?
Would I need the permission of Emerson, Spyderco, and REKAT (don't know if they have a patent on the rolling lock or not)?
I've seen Simonich and Crawford customs with the rolling lock, and a Crawford KFF with a Spyderhole, but have no idea whether they have or need the blessing of a manufacturer.

The question is sort of hypothetical, since I assume that comissioning a maker for a one-of-a-kind folder would increase the price dramatically over one of his existing models, or a modification of one.

Any opinions on the feasibility/cost/time of such a project?

Thanks, just trying to learn a little,
Owen