All ye who cleanse the touch hole with a partridge wing have, I would suppose, a much larger vent than do most rifles today.
As far as the illustrated pick holder, Stephen Pool learnt his trade in North Carolina before moving to Kentucky. When first I saw this rifle, which had just traveled from Kentucky in the back of a pickup, I thought by the stock shape it was North Carolina. One of the Williamsburg guys, and a Pool descendant from Memphis, educated me on that matter. Memphis gentlemen told me the name was originally Pettipool, hence all the census names had "P" for what I thought a middle initial. Shelby Gallien has done considerable research on this, told me the "S" was for Stephen.
Did I digress? Never thought about how that brass tube was attached to Mr. P'Pool's rifle but that does look like the end of an iron pin just above it.
As stricly an Amateur flint shooter I will now spout off my unfounded opinion: - damnd if I could clean the vent on my rifle with a feather. Fouling can be too hard. I have used copper wire - too soft, bends -prefer hard drawn brass vent picks. Our local Champeen says he used a steel needle, careully pushing it into the vent until it hit the far barrel wall. This to ensure an opening in the charge for the flash from pan to ignite.