Collectors with a passion for motorcycles have been repeatedly spoilt with opportunities to buy exceptionally rare classic bikes, in recent times.

Especially noteworthy examples include Bonhams' sale of a c.1894 Hildebrand & Wolfmüller - the first-ever production motorcycle - for £86,200. (Ben Walker, Bonhams' Head of Motorcycles, told us about his auctioning of the bike as you can read here.)

Elsewhere, who can forget the old 1929 Harley-Davidson 21ci Peashooter motorcycle found in an Australian mine...

Now here is another exceptional motorcycle for sale. It also has some Aussie provenance, having originally been sold to a motorcycle dealer in Sydney.

This original 1917 Harley-Davidson motorcycle is auctioning in Las Vegas

And it is truly one of a kind, according to Auctions America (a subsidiary of RM). Auctions America will sell this bike in Las Vegas on January 12-14: an original 1917 Harley-Davidson.

Wartime factory bikes - otherwise known as "specials" - were produced in very limited quantities. And this 1917 Harley-Davidson was among them.

Official documents say that it was listed as a "17 T Twin Track Racer (Magneto)" or a "Stripped Stock Racer."

What's more, factory records say this was the only 'Model T Magneto' model of its kind produced that year - that's out of a total of 18,522 Harley-Davidson motorcycles built in 1917.

Features on the vintage and very special bike include original factory paint and tank decals, and a patent decal on the steering neck.

Other notable aspects are the motorcycle's Troxel seat, pin-striping on its forks and rims, leather wrapped cables and a rear brake hand-lever option.

A closer look at the 1917 Harley-Davidson motorcycle's vintage hardware

As you can see from the photographs, this 1917 Harley-Davidson has withstood the test of time.

Auctions America describes the bike as "untouched and complete ... among the best examples of an original pre-1920 Harley Davidson in the world, this "time machine" remains effortless to start and ride after 95 years!"

This could be a once-in-a-lifetime opportunity to purchase this "one off" Harley-Davidson. You can bet that it will cause much excitement when it appears for sale in Las Vegas, next year.

Watch this space for more news from the collectible motorcycle markets.