Nothing is fake, but the buttplate mostly reminds me of the "Cerocite" material that Adam Cue Company used and probably still uses for buttplates.It isn't? What else is fake on it?
They've been made in both Japan and Korea that I know of. Possibly elsewhere. Also, the ringwork in the joint collars very much remind me of that line as well, though I can't find the exact model. But that may be a good start.
For reference, an ivory looking buttplate can also be various versions of Ivorine. To my knowledge, there is Ivorine 3 and Ivorine 4. Various makers use other composites.
All the best,
WW