Huge oval frame, gilded wood. Any idea what is it?

[tiziano]

Hello All,
I purchased a strange object, as I have fallen in love with it at first sight... It's a huge Oval frame, gilded wood. Size is about 180x160 cm. They tell me it comes from an auction in Lyon, France, and that the original object was a mirror, that was replaced because it was damaged during a transportation. The wood looks quite old, as you can see from the picture of a detail of the back.
Thanks for any feedback!