Sony Speaker Replacement?

I have an old pair of Sony SS-u421av floor speakers. All the speakers in one cabinet work, but in the other cabinet, the mid range is completely shot and the woofer is really bad. I kind of want to hang on to the cabinets and replace all the speakers, especially since they hold 12" woofers (measuring the frame, 10" if not). Should I just scrap this idea and go buy a new pair of floor speakers, or would it be a decent idea to upgrade the speakers in the cabinets?