Carlo Cignani or Domenico Piola

At Schneider-Henn, they sell on 6 May a drawing by Domenico Piola (or "school of") with drunk putti, lot 1041. Very finely detailed and measuring 57 by 76 cm, it is estimated at 800 Euro.

Some searching gave me a corresponding painting, but it is not by Piola (1627-1703) but by his better known contemporary Carlo Cignani (1628-1719). I could only find the above very small picture at Artnet, but it clearly is the same painting.

A companion piece failed to sell at Dorotheum in 2012.

Now, the main question is whether the drawing is a very elaborate and detailed final design by Cignani before painting the work, or a very elaborate and detailed copy by Piola (or someone else) after the painting. The former would be a lot more interesting (fincancially but also artistically), although the latter is still an interesting piece in its own right. I don't know whether Cignani made such final preparatory drawings or what they looked like, so I can't judge it. Most of the drawings I did find were quite different, but those were more sketches, studies, not (apparently) final preparations.