Galerie Moenius, from Switzerland, sells on 18 November 2017 as lot 157 a "Flemish Artist, 16th century" Adoration of the Shepherds, an oil on panel of 56 by 36 cm estimated at 9,000 to 11,000 Swiss Francs. It bears an old label referencing the Master of 1518.
Detail from Adoration by the Master of the Lille Adoration
The work and artist surely must be situated in that period and region, although the extremely elongated neck and posture of the Virgin perhaps even more resemble some works by the Master of the Lille Adoration.
But for some reason, the whole reminds me most of Jeroen Bosch (though lacking his pure quality of course, it is at best a follower of his work). Some details, like the very curious miniature shepherds on the wall, or the man (Joseph?) in the background with a candle on the ground, give me a true Boschian feel.
And the shepherd with the bagpipes on the left is rather similar to the central figure in the Wayfarer. Admittedly, they are rather superficial similarities, not clear derivations, but all in all the work is quite different from many other at first similar Flemish Adorations in ruins from the same period (1510-1530), thanks to the unusual details. Things like disregard for perspective are quite common, but getting a life-size shepherd and two miniature ones next to each other like this is virtually unseen (miniature angels are quite common, but these two clearly aren't any angels).
The only somewhat comparable whole work by Bosch (or rather, known from copies after him) is the above Adoration, with a quite similar Virgin. As usual, I found this through RKD.
The painting will likely remain anonymous, and the estimate seems about right, but it is intriguing nevertheless.