I am a big, fat liar... I could have sworn I used a pulled rivet but turns out I used a driven rivet.
I used an old wood chisel. I used the grinder to dull the edge and then put a couple pieces of duct tape on the tip of the chisel to avoid scarring the rib. Elevator goes on top of the back-rivet plate. Chisel goes on top of the shop-side of the rivet. Rivet gun driving on top of Chisel.
You might want to try a few test pieces because the chisel tends to drift a bit. You want to keep it pretty flat and steady.
This is a bit of a pain but once it's done, you'll quickly forget about it
Here's an EAA video that covers this very thing...
http://eaavideo.org/video.aspx?v=5337092001