[EdHolland]

What I used was art card stock matched for thickness and weight - it wont be perfect, of course. However, I reasoned that it is very hard to match what was used originally, especially where one has to make a judgement from the 80+ year old material of the old cone. Even in good condition for its age, an old speaker may not sound like it did when leaving the factory - what I was presented with was so fragile it would barely hold itself together.

From the limited testing done (I could take this further and mount the speaker in the cabinet for the full effect) I considered the sound/tone to be very acceptable. Proof of the pudding will be feeding it from the 42 P-P output stage with honest to goodness AM radio.