That is a cup type buttplate, not a Siamese Mauser butt plate. That type buttplate would require even more work, since the wood has to be inletted all the way around.
I guess I don't quite understand what you are trying to do. I forget whether the Turk has a trapdoor or not, but I didn't think so.
If the Turk buttplate is a standard Mauser type and it is worn or damaged and you just want to replace it with the original type, Gun Parts Corp. has Mauser 98 buttplates for under $5.00 and those should fit. If you want something different, then you will have to fit whatever you want.
Jim