Royal Enfield Fury: very fast, super rare, but they're out there if you look

I've written with reverence about the Royal Enfield Fury, a very rare model of the single-cylinder Royal Enfield Bullet. Its distinguishing feature, I gather, was that the Fury, built in Britain, had the "Big Head" motor, along with other parts that made it go fast.

It all started in 1960, according to Ian Chadwick's The History of The Royal Enfield Bullet:

"Huge, one-piece alloy cylinder head ('Big Head') casting... The Royal Enfield Fury, produced at this time for the U.S. market, is essentially the same bike as the Bullet (both 350 and 500cc models), capable of reaching the 100 mph mark... It differed from the Bullet by having a larger inlet port, an Alfin aluminum alloy barrel with cast liner (instead of the Bullet's iron) and a higher compression piston (8.9:1 instead of 7.3:1). It also had a flange for mounting an optional rev counter, an 18-inch rear and 19-inch front wheel. Between 1959 and 1963, only 191 machines were made. The 500cc boasted a 40 bhp output, up from the UK models' production of 27 bhp. A 600cc model was also made for a short period. "

With so few made, I never thought I would hear of one and, yet, in the last few weeks I have been contacted by no fewer than THREE readers who have — or appear to me to have — Royal Enfield Furys. I am asking for you readers to help me out here. I am not enough of an expert on these things to tell, for sure.

First, let's look at the pictures here of a Royal Enfield Fury emailed to me from Couturier Francis, who is offering it for sale near Reims, France. Rather than expose his address here, if you want to buy it, just email me and I will forward your address to him. He prefers to communicate in French.

My French is not good, so I have been able to get only a few details about this lovely machine. Here, with the help of Google's language tools, is what CF has told me:

"The price is €8,400 (there are some parts included). Contact me in French if possible (I do not speak English well). The Fury is equipped with Big Head, 50mm exhaust valve, all-aluminum cylinder, special (9-1) high-compression piston, racing cam, GP 38 carburetor, racing magneto, close-ratio racing transmission, K-81 tires. New paint and mechanically restored."