In a nutshell then. I'm playing a BBb bass. It has a Vincent Bach 24AW mouthpiece which I like playing on. But it has an area of nickel plating missing on rim. The base metal is in contact with my mouth/lips. Need a new one. Can I presume that all VB mouthpieces will fit my BBb leadpipe. But if I bought another brand of tuba mouthpiece (will use Wick as an example) thenI would need to order one with 'large' shank.