These days, at least in the US, liverwurst is a pretty niche product. Maybe try a local specialty butcher or sausage manufacturer?

Or you could order online from this deli - https://www.zingermans.com/Product/usingers-smoked-liverwurs...

(Though I'd wait for cooler weather, and "Ships frozen" probably won't be cheap.)

Good tip! I’ve been to Zingerman’s, it’s a cool place. Funny how what used to be a deli staple has become a special-order luxury.