TubeNet

Contact Sam Gnagey. He can help you. My Holton/King Frankentuba came with the old style (small) buttons. I got a new set of the newer King (large) buttons from him. No pearl inset, just plain lacquered brass, very nice, slightly concave. Be aware that you also need to replace the top cap on the valves for these to work.

SK

I think Sam Gnagey can get them. Also, Yamaha buttons have the same threading (i think?).

While the main discussion here seems to be about creating a "stock" look with the replacement valve buttons, I say go for whatever works the best for your hand size. When I had Dan Oberloh to restore my Holton 345 I told him I wanted the newer oversized valve buttons, so he installed a set of nice large diameter MW pearl inlay valve buttons. My past experience is that my index finger tends to wrap over the edge of the smaller first valve button and causes the valve to be depressed with angular pressure on the stem. Over time, this causes uneven valve wear and visable damage the the valve plating. With the larger buttons I can't wrap my finger over the edge of the button, so I wind up depressing the first valve straight up and down and no longer get uneven wear on the first valve. Plus my little finger no longer slips off the 4th valve button the way it does on my other horns. So now the valves will last longer and perform better. Shouldn't that be the real goal?

+ 1,000 on Bloke. You can order the buttons and caps for the King buttons from Conn/Selmer; I don't think Allied has them yet, but I'll have to check my new price book for a new part number. But you have to be in Conn/Selmers' network to order from them. Call Sam.

You can also make your own with the right tap if you're brave!