Brief Description: Complete dimpling RH skin with pop rivet dimpler
Yes! A worthwhile sleep, and slow consideration of likely places for the missing die to end up resulted in me finding it within 10 minutes this morning. (It was nestling in a box that was on the lower shelf of the castoring worktable).
So, back to dimpling the skin resulted in me going through a couple of dozen nails in the pop-rivet dies. Having learned my lesson from yesterday, I backed the female die on the inside of the skin with a cushion, so that it couldn't spring off into the ether again.