Help with IDing Pistol Grip

[Gottlieb]

I'm doing research on this part, which I have provided a photo of below. This was butt-stock was made from another butt-stock, for a custom application by a now defunct company. Looking closely at the piece, I can tell it was not made from scratch, but was modified from something "factory." Does anybody have any leads? Whatever it was made from, it's aluminum, and the pistol grip and tactical butt-stock were part of the original intended purpose. Thanks in advance.