Antoine Caron, Tiburian Sybil, French Renaissance

For sale at Prunier (lot 61), 15 February 2015, with an estimate "available on request"... (Update: according to the Gazette Drouot, the estimate was a reasonable 100,000 Euro. I haven't been able to find the result yet). Attributed to Antoine Caron, a relatively important 16th century French painter, it's a copy / alternative version of a painting by him kept in the Louvre, with nearly the same dimensions (132 by 174 vs. 125 by 170).

Remarkable differences: the medaillon hanging beneath the golden bird (near the top, slightly to the left, between the turned pillars) is missing in the one now for sale. The fountain on the right is clothed in the version for sale and nearly nude in the Louvre version. At the top left, the Louvre one has two medaillons above each other, while the new one has an architectural element as the very top one. Apart from that, they seem to be nearly identical, with the same colours, elements, and so on. The one for sale has brighter colours, but that is probably due to condition, varnish, cleaning, ... and not really a difference between the versions. The auction site shows some details of their version, indicating the high quality of the painting (for that time and period). I see no reason to doubt the "alternate version" theory, it seems too good to be a later copy. What's it worth? With the damage, I would guess some 200,000 to 300,000 Euro. But I'm really way outside the limited expertise I might have, so the actual estimate and sale price may be completely different obviously.