Altec 416-8b drivers vs new GP reproductions

Does anyone have experience on the sound differences between the old Altec driver and the new Great Plains reproductions. They look like a drop in replacement, but is the sound the same, or maybe even an improvement over the original drivers?
They did an EXCELLENT job with rebuilding my woofers in my Altec 19's
I sent both woofer to them for a total rebuild and the Magnet's Re magnetized because of the age of the woofers, from what I understand
they purchased the original production equipment from Altec and employed some of the original employees, I sent them a list of what I wanted done and a money order for I think under $300.00 after I had a nice conversation with them, Because they need to know your drivers are on there way to them.I have heard the drivers made by them and you can't tell the different between the old and new. last I heard was they may close up shop to retire, that is why I quickly sent my woofers in.