first one is of the "broken-glass" type, pretending to be an engraving which has fallen down, and where the protective glass is broken. It is only estimated at 300 to 400 Euro, but it isn't the most refined example of its kind. The best examples of the kind are by Etienne Moulinneuf (1706-1789), but this is an anonymous example. I can't find any reference to this engraving, it may be an invented one for this painting. The signature or text at the bottom references an "Abbé Bousquet", but I can't find any abbot Bousquet who meddled with this kind of thing either. The estimate seems about right.
UPDATE: sold for 1900 Euro, 6 times the estimate!
UPDATE: sold for 1,400 Euro, nearly three times the estimate but not as much as I hoped for.
The whole is painted with great precision and immaculate detail. The actual trompe-l'oeil effect, the 3D effect as we would call it now, isn't the most convincing (though pretty good nevertheless), but the artist seems more concerned about getting the documents right in the first place.
Considering the dates of the recognised documents, it may have been painted very shortly after the revolution, although it may also have been created after the 1830 revolution to commemorate the earlier attempt at independence and the "heroes" of that episode.
I haven't found any other similar work (a few trompe-l'oeils commemorating the French revolution, but not of this quality or historically important iconography). Estimating such a one-off is difficult, but even purely on artistic merit this one is not expensive, and because of the interest it will have for history buffs, numismaticians, Belgicists, ... it may fetch a lot more. One to watch!
third one is a "Perpetual calendar" decorated with a trompe-l'oeil! The work, estimated at 300 to 400 Euro, is signed by a Jacob Andreas Eisenman from Nuremberg, and one of the documents has a date of 1779, but I haven't found further information on the artist. It isn't the best trompe-l'oeil in itself, but the combination with a perpetual calendar (or with any moving elements at all) is new to me. It should be worth closer to 1,000 Euro for lovers of calendars or of the quirky.
UPDATE: sold for 800 Euro, more than double the estimate and about what I expected.
fourth lot of trompe-l'oeils has two fake Teniers engravings and one fake image of a bird. Nothing exceptional here, only estimated 400 to 600 Euro for the three though.
fifth lot is a bit rarer and has two "damaged" works of art. The auctioneer attributes it to Germany, 18th century, and I have no reasons to doubt this. Estimated at 400 to 600 Euro. Not particularly well painted, so probably not worth more either.
UPDATE: sold for 600 Euro.
sixth lot is another more common and mediocre version. Nice to see an engraved portrait of Cornelis de Vos in it though. There is also a seventh lot of four further examples. The eight lot has two religious trompe-l'oeils by Crijn van Zuyderhoudt from 1777.
UPDATE: 6th and 8th unsold, 7th sold for 600 Euro.
Lot nine is a simple but nice example by Amedeo Seyter. This one seems to be severely underestimated at 300 to 400 Euro. Similar works fetch between 4000 and 18000 Euro elsewhere. It has condition issues though: the "scagliola" (fake marble) support is cracked, and the drawing is dirty. Even so, this is a rare thing and a highlight in this selection. A much larger one sold at Sotheby's in 2012 for £21,000.
UPDATE: sold for 1200 Euro, 4 times the estimate.
The tenth and final lot is a gravure trompe-l'oeil. Estimated at 300 to 400 Euro, which seems a bit high for a fairly common work which was recently sold for 180 Euro.
UPDATE: sold for 2,700 Euro, way more than I expected.