Hi arnl,

Being 40cm tall and only weighing 1.7kg I would imagine they are not metal. I don't think they are porcelain either due to the tennis racquet. Porcelain wouldn't allow such a structure. So your next option is resin.

If resin, then they are not old or terribly valuable. Another hint to value is that as you stated they are unmarked therefore most likely mass produced in a mould.