The "Old Bloke" did it, he rode his 1910 FN Four Cylinder "Effie" from Tibet to Belgium just to see if he could. His name is Ron Fellowes and he is almost 70 years old ! I posted some write ups when he first started his trip and I followed him most of the way and then got side tracked. He is now writing a book about his adventures.
Check out his blog here
http://oldblokeonabike.com/