Here's an original cel from Shimai Ijiri (Slave Sisters), a Japanese hentai anime show from the 90's.
Cels are used to create the actual anime and are rare and unique in nature.
This 2 layer cel is a complete set as it comes with the original, matching background and with douga, the sketch which is used to create the final cel product and also a layout (copy - picture 4).
The cel features Yukari in the second episode (the infamous dream scene).
There is no trace of vinegar syndrome: no smell, no waving.
There is no sticking to the background, there is no sticking to the sketches.