I actually countersunk the tang bolt completely last night. There was a few loose ends I had to finish...sights, ramrod, finishing the barrel (which included countersinking the tang bolt).
Thanks for the complements. I look to improve the lock panels a bit on my next build. Not sure if I over think too much, but they are tricky for me.
I've got all my parts for a lefty Isaac Haines from Dunlap - good looking piece of wood to boot!