String-through ferrules in place. This is the bottom of the guitar, the strings go through it to meet the bridge on the other side. As you may notice, the holes are not exactly aligned, but I guess that doesn’t matter a whole lot.
These “cups” are commonly pressed in using a drill press, vise or just hammered in. I’ve read that some people press them in using a soldering iron while heating them u
I found them fitting quite snugly, so I used a piece of wood (protecting the finish) to bang them home with a hammer, I can always use a little drop of superglue to adhere them if they ever loosen. 99% of the time they’re held in place by the string tension itself.
Note that you can see the high E-string grommet in the bottom ferrule.