All of my "noise makers" are mainly stainless and range from one with 1/2" bores to 1" bores and finally golf ball bores. All of my stainless pieces fit into a large fire safe (the kind you'd put important papers into). Beyond that I have two pieces that won't fit anywhere except on display. One is a large golf ball cannon and steel carriage, the other is a huge golf ball bored Thunder Mug that's 10" in diameter at its largest and over a foot tall. It was for these last two I was looking for a Tompion to keep the bugs out.
While shopping one day a Lowe's I came across a rubber stopper that looked just about right. It fit into the bore but if you gave it a good pounding it would sink into the bore, so.... I picked up a couple of 5/16ths bolts and same for two different diameter fender washers. I then found two threaded knobs with the same thread. So the bolt goes through the smaller washer into the stopper at the small end and comes out the stopper through the larger fender washer and finally into the threaded knob. It's a simple matter of putting the Tompion into the bore and giving a couple of cranks on the knob to tighten it up and lock it into place. Works like a champ. Smithy.