removing glass shine from a painting

I guess it would depend on what mesh you cloned. If whatever you cloned has a separate mesh group for glass, and you don't want glass, then you'd want to clone something that does not have glass.

TS4 uses the PhongAlpha shader for transparency. For non-transparency, TS4 uses Phong. Typically, a painting that has glass will contain at least two mesh groups: one for the glass, one for the rest of the mesh. It's set up this way because each mesh group requires a different shader.

Again, if you don't want glass then clone something without glass like a poster or something.

If your custom mesh has a mesh group meant for glass than just delete that group in Blender (press X > Faces). You have to make sure your custom mesh has the same number of mesh groups as whatever you cloned. And the cut numbers have to match, as well.