I recently purchased 12 Bose 901 series 4 speakers (late 1970s early 1980s) from a rollerskating rink that was upgrading their sound system. Two of the 12 speakers work okay but the rest barely work. The sound is very crackly and muted. I assume this is because the surround foam has disintegrated. My question to the experts out there: should I buy a surround kit for the speakers to do myself and then try selling them? Or should I leave them alone and try to sell them as is? Does anyone know the value of these speakers as is or resurrounded? I do not have the pedestals and I do not have the equalizers. The bodies themselves look pretty good as well as the screens. Any help would be greatly appreciated. Thank you in advance.