This water gilded, late 19th Century slip had been overpainted with gold paint, you can see in the photo above how it has gone a lovely browny bronze colour due to oxidation. This layer of paint (it would have originally been gold) was easily removed with acetone, which reveals the original water gilding in gold leaf.
Why was it painted over in the first place? well the gilding is quite distressed and rubbed away in places. A classic cause of damage to the water gilding is someone giving it a wipe with a damp cloth, this removes the protective coat of size or ormolu and makes a mess of the surface. The more cleaning and rubbing, the worse it gets so the solution was to tidy it up with a coat of gold paint. The slip is not actually that badly damaged, and personally I think it looks good with some rub through to the bole.
