I keep my eyes peeled for sizers all the time. One other source is your local "closeout" store. I have purchased a few "imported" glass bottle sizers for less than a buck that once held sparkling water, tomato juice, salad dressing, etc. My favorite sizer is a narrow handle-less coffee cup from an Ikea store. I rough these up a little with my belt sander to help them grab the horn better. I also have used the flower pots. They are good for "keeping" your horn round while you are not working on it, and/or before you put the base plug in. I usually size more than one, so its nice to have multiple sizers, or flower pots after the fact, for that.
Top Jaw