The Estafette is up for auction by Silverstone Auctions at CarFest South with an expected price of £15-20,000.
Rush is set in 1976 but the Estafette changed very little between its inception in 1959 (as part of a plan to rebuild post-war France) and 1980, when production ceased in France. In 1978 a 1.3 litre water-cooled engine was introduced, which powers this van.
This Estafette spent most of its life as a fire truck on the French/Swiss border. In 2012 it was bought by a Brit and moved to the UK. Shortly after it was talent-spotted by the Rush producers.
Here's the link to its page on the Silverstone Auctions website.