Almost impossible to find, brand new copper S&B Volume Control Transformers (TVC). These are not being sold retail anymore at all.
S&B is considered the premier maker of TVC transformers. The factory is selling assembled TVCs for $2500 under the Music First label so you can save a lot building your own.
I bought these for a DIY project but no longer have the time so I bought the Music First TVC. I have wiring instructions from the factory which I will include. The shielding cans are treated with C37 Lacquer.