Adam. My philosophy is this. "if a jobs worth doing at all, then do it right.". Mate dropping the tank it a piss job. Get it dropped, remove it, and then you can empty all the crap out of it while ya there. You can also remove the filler neck then too and paint behind properly.
here :
Your doing a good job, and by the looks spending quite a bit of money on new bits, so why not just go that little farer???? At the end of the day its only time not money