Hi Sloboat,

On stuffing boxes that sit below the waterline, I solder a 4mm brass tube onto the stuffing box and drill the stuffing box afterwards with a 3mm drill in a Dremel.
The fast rotating drill is guided by the brass tube and it requires little pressure to make the hole.
It's wise to hold a wet cloth on the soldered joint though, to prevent the solder from melting, should you drill too slow, heating up the solder.
Remove the burrs before assembling the stuffing box.

I use a syringe with a piece of silicon tubing to fill grease into the tube.

I added a pic of the grease tube in my 63 cm tug hull, I capped the 4mm brass tube with a fitting plastic cap I found in the Tiger Plastic range. I'm sure you can find something similar (but, as mentioned above, if you use grease, it's not really necessary)

Just make sure, the grease tube sits roughly in the middle of the stuffing tube and doesn't get blocked by bulkheads or other restrictions.

Regards, Jan.