Drixton 500cc Racer

The famous modified Honda 450 Racer prepared and offered by Othmar "Marly" Drixl. I wonder how many copies of this frame have been made in recent years for the legions of 350 and 450 Honda vintage racers.
http://curtisracingframes.com/road-racing.html

A reader points out that there appears to be at least two different frame designs from Marly Drixl and this is not one typically seen today. I've updated the post with the complete article in the August 1970 issue of Cycle World and added an image of the more common frame below. 

http://motoringworld.in/features/true-original/