I found these bells in a local shop. They're beautiful, solid brass, and have a great sound. I picked up a #1 dog bell for $8. They didn't have anything bigger at the store except for door ringer straps, which are huge things. I'll probably order a #4 dog bell or larger. They make bells up to 2 7/8" (73 mm.)
I don't have a financial interest in these guys. I just love their bells.