The Peter Dicks driver parts ways with the Ohm driver in several ways. First of all, it was modeled more accurately. While Walsh was a genius (and so was DaVinci), he was unable to accurately model the concept in a way that would make it reliable. Dicks was able to do that.
Dale Harder of
HHR Exotic Speakers has been refurbishing Ohm A's & F's for quite some time now. He completely replaces the cone surrounds, new cone material with a lighter mass, and voicecoils using newer materials and technology. He now makes his own versions(TLS I & II) of the Walsh drive speakers and claims that he has solved the power handling and voicecoil issues of the past with a new driver that is more efficient and durable. Here is a
list of the improvements(.pdf) he's made on the original designs with his new speakers.
TLS I & TLS II specs(.pdf). Here are
pictures from his website of how he makes the new speakers.
Dale seems to have more hands-on experience and knowledge of the Walsh designs than just about anyone out there. I'll send him and email and get him to join this discussion.