Praxiteles rediscovered: the original works

Any exploration of the question of original works of Greek statuary is confronted with the sad fact that most of the great sculptors of the period created their masterpieces in bronze, and that many of these have since been melted down for other uses. Happily, Praxiteles also produced marble statues.

Do any tangible remnants of Praxiteles's work survive? The question is a source of controversy among archaeologists and art historians. The ancient texts imply that Praxiteles worked on the decoration of the altar of Artemis at Ephesus (according to Strabo) and the mausoleum at Halicarnassus (according to Vitruvius), but the sculptures discovered at these sites cannot be attributed to Praxiteles with any certainty. And are the surviving statues original works, faithful copies, or pastiches expressing the tastes and fashion of their time?
Two examples illustrate the various expert approaches to the question.