Jacob Ochtervelt or Pieter de Hooch?

Duesseldorfer Auktionshaus, from germany, sells on 25 November 2017 as lot 278 a "Dutch Master, 17th century" musical scene, estimated at 400 Euro.

The scene is typical for Jacob Ochtervelt (1634-1682), although with this quality it would be one of his weaker works. Sure enough, the painting was sold as by Ochtervelt in 2007 at Koller West for 4,000 Swiss Francs (some 2,500 Euro). This would mean a serious loss for the seller (who ha enjoyed the work for 10 years, so when one would consider this as a lease, then paying 200 Euro per year to have  this on your wall is not excessive). It is unclear why the auction house doesn't mention Ochtervelt, even to simply call it "School of" or "Follower of", as this work clearly is by or after him.

The Lemon Slice

A Child and Nurse

Ochtervelt was a pupil of Nicolaes Berchem, together with the more famous Pieter de Hooch. They are best known for interior scenes, often involving music making; many of his works feature a dancing dog similar to this one.His standard works fetch between 10,000 and 50,000 Euro, while his truly good works get sold for $600,000 ("The Lemon Slice", Sotheby's 2008) or even $4,000,000 ("Child and Nurse", Sotheby's 2014)!

The Dancing Dog, 1669, Shenandoah Museum

Dancing Dog, 1669, Wadsworth Atheneum

This work is far from those dizzy heights of course, and is much closer to the above works. I guess it should be worth about the price it fetched 10 years ago, 2,000 to 3,000 Euro; the current estimate is way too low.

Apart from Ochtervelt, there is one other name who regularly made similar works: Pieter de Hooch. These works seem to be among the weakest works by De Hooch though, so I wonder whether these aren't by Ochtervelt instead (who at his best made very fine orks, but seems to have made more mediocre works than e.g. de Hooch). The above wa sold at Sotheby's in 2000 as a De Hooch, is signed, and is accepted as by De Hooch at the RKD: but the quality seems really below what one might expect from him, and much closer to the work for sale. Still, it sold for $137,000, so what do I know?