I'd be very interested in hearing about your source for vintage 6x9 4Ω speakers as replacements in
the AD radios.
Replacing cones and coils are not as easy as it may seem. I've found getting exact replacement parts for
these old style speakers is near impossible. If you rebuilt that speaker in the linked pictures you need to
offer that service to the public. That is an extremely professional job of rebuilding and I would love to hear
more about how you went about that.
I did stock up on replacement 4Ω speakers when I rebuilt mine and a friends original AD radios.
Electro-Tech Inc. in MN carries a pretty extensive line of vintage style speakers.
http://turnswitch.com/ The 4x9 4Ω speaker from them runs about fifty bucks.
Denny G