I bought a couple of new-in-the-little-tube Sengbusch nibs at an antique store for three bucks each. They look the same as Estie nibs. Are they interchangable?

I have heard that most are. Sometimes there's an issue of the length of the nib in relation to the cap--not all Esterbrooks are Js. But I don't know from experience.

Good deal at $3, though.