BJ, you did good.
Those types of beetles I have seen many times when I didn't remove the bark even for just a couple weeks, and the wood is fine, BUT!!!
As a warning to others, I have debarked elm, found stuff like that, made a bow soon after nad been fine, HOWEVER, if I left it around a few months, I always came back to the stave full of holes anyway. It's like the eggs are there, the drying retards their turning into grubs, but eventually they do and will eat the wood, too, or maybe it's a different beetle, but if you see that wiggly pattern, don't dawdle on the bow.
As for tools, you wouldn't believe the hodge-podge of weird stuff I have accumulated over the years, and it all works, and I always go back to each of them eventually for some little task. If you have a good vise, I chase rings on the regular with a light mallet and a big sharp chisel, even. On elm, just leave yourself some margin of error to scrape/file down to. It won't usually tear-out down through nice distinct rings, but it can.
