The predecessor to today’s Focus, the Ford Escort was always supposed to be a budget proposition. That much more so, you might think, decades later. Yet this one’s coming up for auction with a pre-sale estimate of roughly $85,000. So what gives?

Well as you might have guessed, this is no ordinary Escort. It’s a 1972 Escort RS1600, a factory rally machine with an engine more closely related to a Formula 3 racer than a showroom-stock, bargain-basement econobox.

The spiritual precursor to today’s Focus RS, the Escort RS1600’s 1.6-liter straight four was built by Cosworth with 16 valves, placed in a beefed-up chassis crafted at Ford’s famous Advanced Vehicle Operations (AVO) within the Aveley Plant in South Essex. It’s rather justifiably described as “the genesis of the RS breed and the ‘holy grail’ to classic collectors” – a veritable rallying icon of its era, of which few have survived in such immaculate shape as this one.

This example was specially ordered in this vivid shade of Le Mans Green and has undergone a comprehensive restoration, since which it’s driven just 3,525 miles (5,673 km). Of just 1,137 such RS1600s believed to have been built, this is one of fewer than 50 currently registered in the UK. All of which adds up to a rather princely price (for an old Escort at any rate).

Silverstone Auctions will sell it to the highest bidder at the Dallas Burston Polo Club in Southam, UK, at the end of September. The auction house expects it to sell for £60-70k, or roughly $78-91k at current exchange rates.