i believe the frame u get now from arlen ness is not exactly the same as mine, (you would get a later version)
i bought a new version cast ally petrol tank from arlen ness ("via jpcycles cus arlen ness wont deal with us foreigners") and had to make n weld new mounts to the frame, my original tank was made of "fibre glass" which of course cracked, bike being a hard tail. The previous owner had this problem and had cut out the bottom of the tank to make it just a outer decor cover, covering 2 smaller tanks mounted either side the frame "capacity 1us gall", cant ride far on that especially as i had issues filling to full cus of air lock/ cross over vent between tanks, so i purchased a new tank from arlen ness via jpcycles cus arlen ness wont deal with us foreigners"