Repair/exchange of replacement tweeter

A few years ago I bought four RD0194-1 tweeters as replacement for the old production tweeters on my SDA-1Cs. They *sounded* fine except for a 16kHz ring in one of the tweeters that nearly never occurred except in one musical piece where there was a sustained 2-second tone at this frequency. Later when I learned to use REW, I did several frequency sweeps that I've just learned lately to examine as to the distortion profile.


As you can see, there was a huge spike/plateau of distortion above 1kHz. I've already bought a replacement tweeter, but wonder if Polk can "refurbish" or repair the old tweeter, so I'll have a spare ready should this problem happen again in the coming years.
Polk SDA-1Cs with RD0194-1 upgrade tweeters, SoniCaps, Clarity PX, Gimpod boards, Cardas BPs, Erse inductors, Canare 4S11 IC; Yamaha Aventage RX-A1080; Yamaha M-80; Yamaha C-80; Yamaha CD-S1000; Sony UBP-X800M2; Technics SL-1400 with Ortofon 2M Bronze PnP; Vincent Pho 701; PS Audio Dectet; AudioQuest Red River ICs; WAudio PCs; RapcoHorizon High Def High 413-Strand 10AWG Speaker Cable; Auralex Isolation Pads