The painting before treatment shows layers of discoloured varnish and overpaint, all covered by a heavy layer of surface dirt. The surface was matte and brown and it was difficult to make out many of the details.

As the varnish was removed, it became clear that beneath the figures of Jupiter and Juno there were additional legs, painted in a strong red very similar to the colour of Jupiter's other limbs.

The conservation team examined the painting with different light sources, including ultraviolet light which helped locate layers of overpaint, which are dark in UV, as seen on and around the figure of Juno in the image below. 

An x-ray of the painting helped to identify changes beneath the surface and Juno's original foot could be seen clearly emerging beneath the hem of her dress, complete with its sandal.

Jupiter's left leg was also visible, stretched out diagonally across Juno's body.

These parts are visible as the paint used has a high lead and vermilion content; both pigments contain heavy metal compounds and appear pale or white in an x-ray image as x-rays cannot pass through them.

Once it had been established that changes had been made to the figures at a later date, and that earlier limbs were present and complete beneath the overpaint, the team decided to make some exploratory cleaning tests. Only if the overpaint could be removed safely would we proceed any further with the cleaning.