I used the rubber mounts from the old cooler and one from an old car hooter (horn) bracket. Make angle brackets from 16G alloy and drill/tap the frame. Make sure the bottom steering yoke clears the cooler top. The cooler has to be fitted upside down so needs a bleed screw into the RHS top. I used a small self tapper and washer.
Dont use 10mm compression elbows. They shake loose and leak. How would I know.
Biker since 1975. Ex engineer turned chiropractor.