Howdy- quick update. Mr. Richard So of Richard So Electronics at adsspeakerservice.com replied to my request for information and confirmed that he is indeed still repairing A/D/S/ speakers. The site again is:
Mr. So indicates that he is the only one using original A/D/S/ parts to repair these rare speakers. If you are an A/D/S/ fan, I highly recommend that you read the "about us" on his website, as it provides a brief history of this iconic audio company. I do not currently have a need for speaker repair as my L470s are in great condition, but I will definitely keep him in mind when I find that pair of L1590s that are in need of some help!