Ah yeah good shout on that. I do have the grate + ring that you mentioned. Might have to get some wire to do as you show.
Shaken up the coals and there were about 1/4 at the back that weren't even lit it seems. Gave it a good move with a spoon and a lot of the excess ash fell through.
Don't use the charcoal grate that came with the WSM! You'll need a charcoal grate from the same size of a weber kettle. This also helps in that you can set up the two grates so that they run 90* from each other and you'll not have the smaller lump and briquettes fall thru and be wasted.