Fenix P1D/P3D Pocket Clip?

[PkdMslf]

Looking for a pocket clip for my P1D and P3D. I read on another forum that the clip from a River Rock 1AA flashlight will work but I cannot locate one. I did get my hands on the River Rock 2AAA light and that clip works on my L1D perfect. Are there any other alternatives? Is the case of the P1D/P3D thick enough to drill and tap to install a knife pocketclip without screwing up the operation of the flashlight. (I'm new to this flashlight stuff so please bear with me).