Replacement head for my Tony Dixon alto A brass whistle in USA

Whistle
1

I’ve have a Brass Tony Dixon alto A whistle for a while. It’s picky due to what I thought was breath control. I’ve been playing it more and it sounds better but still sounds like it’s leaking air. I decided to replace plumbers tape and realized there’s a fine crack on head. It’s at base and is thin but goes all the way through. To avoid tarrifs does anyone know where I can get one in USA? I think I bought it prior to 2018. The picture of replacement whistle heads I’ve seen online look different than mine. They change size halfway up where mine is basically the same size below the blade. Any input would be appreciated.