Somebody posted up some photos of their radials not so long ago (like last week) as I remember looking at the brackets for the reserviors myself.
I think they put a slip of metal into the clamp of the radial (where the two halves bolt onto the bar) and then it was bent out into the right shape to attach a small 15ml reservoir. No point in having a huge reservoir, as long as you keep an eye on your fluid.
Have a browse through the pics section, or in this section, to see if you can find it.
I'd rather die peacefully in my sleep like my Grandfather, than screaming in terror like his passengers.- Jim Harkins