Do I NEED to fill in that dot for any reason?
To have the pipe "look right" at arm's length, search
Lacquer-Stik Fill-In Paint white
on Amazon (or equivalent) and getcha one.
It's a tube of clay-like thick pasty paint that's designed to be scrubbed across depressions, leaving some behind. Just be sure to wipe away the excess before it dries. Stays white over time, is durable, etc.
Replacing the dot "properly" with a piece of celluloid rod is a
VERY delicate business. Perfect axial alignment of the drill bit and dot hole is required to avoid making it oval/oblong; and fashioning a tiny rod of it takes the right tools and a steady hand. Don't let some hobbiest take a swing at it, cuz there's no rewind button.