I come from the live concert and studio side of loudspeaker design. If you have the original baskets for the cone speakers, and you can find a reputable recone man, many of the original recone kits are still available in back catalog. Just a few short years ago I reconed my JBL 4333’s with the original foam surround kit. Also, for the do it yourself, check out the work being done by the Italian speaker and compression drivers manufacturers B&C and 18 Sound. Precision made motors with excellent specs, cost effective as well.