Got this little shotgun a couple weeks ago. It’s an I Hollis 24ga single weighing in at just under 5 pounds. Old straight through nipple had not been out since Moby Dick was a minnow. Soaked breech area in evapo rust then liquid wrench for a day or so. Some needle nose vice grips were used to break it loose. Still had good standard size 1/4-28 threads thankfully, so a new nipple was installed. Also had to make a new tapered loading rod. Bore is about as good as these old guns get and I have lots of 24ga wads and cards.