Alexander Wiskemann or Dirck De Quade Van Ravesteyn

Bonham's, from England, sells on 5 December 2018 an "Attributed to Alexander Wiskemann" Venus and Amor, estimated at 21,000 to 29,000 Euro.

They give an extensive provenance, including a sale at Im Kinsky in 2010. It was offered there with an estimate of 20,000 to 30,000 Euro, and failed to sell in the regular auction (it may have sold during the aftersale).

It seems to have been offered at Teeuwisse in 2011 as well.

A different or uncleaned version of this painting was sold at Neumeister in 2008, with an estimate of 30,000 Euro. It was attributed to Dirck de Quade van Ravesteyn.

I understand the attribution to Ravesteyn better than the one to Wiskemann, as the Venus here shares similarities with Venuses (Veni?) in other works by the artist. But these Ravesteyns show a more accomplished artist, so at best it would be a "circle of" or "follower of" him.

Alexander Wiskemann on the other hand is a nearly unknown painter, and I have not found any comparable paintings. So I have not the faintest idea why the attribution to Wiskemann is given, it doesn't seem to be based on a signature either. Strange!

UPDATE: the composition is close to a 1610 work by Mattäus Gundelach, sold at Dorotheum in 2011 with an estimate of 60,000 Euro. I don't think the artist of that work and the one for sale are the same though, but I wouldn't be surprised if one artist lies at the basis of both.

UPDATE 2: not sold

Venus and Amor: De Quade de Ravesteyn or Rottenhammer

For sale at Ventes SARL May in Roubaix, 16 March 2015: a "Venus and Amor", attributed to the
Prague School, environment of Dirck De Quade van Ravesteyn (1565-1620). Estimated at 6,000 to 8,000 Euro, it seems to be a good picture, but the only picture I found is much too small to judge it correctly.

The topic has been painted multiple times by Ravesteyn, e.g. this one sold at Christie's in October 2014 for 9,375 Euro. While there are obvious similarities, from the overall composition to the position of the legs of the Venus, the differences are too big to situate this around the same artist (and the one for sale seems to be a better picture as well).

To me, it seems much more likely that the work comes from the environment of Hans Rottenhammer (1564-1625), active at the same time and places as Ravesteyn. There is e.g. the above by Rottenhammer from Christie's in 2010, sold for £58,000.

This one is more closely comparable to the one for sale now. These two make it clear that the painting for sale is not by Rottenhammer himself, but the figures are closer to him than to Ravesteyn in my opinion

For what it's worth, all these seem to go back to a Venus and Amor by Quentin Massys, vastly superior to any of these. And of course the Venus paintings by Titian, like the one below. The Massys is earlier than the Titian though!