Great idea Jim
and very nicely done 
I’ve tried adhesive magnets before, but these burners get very hot... does the base of your holder get hot or is there enough metal for the heat to dissipate?
Nick that was my thought behind using aluminium in the top half and brass for the bottom half (the brass join at the bottom is silver brazed) still deciding whether to cut out some square sheet brass for it to sit on.
I don't think from my short testing that it will get hot enough to scorch the hardwood.