Here's a link that might be useful for you in your quest to restore your AR-3.
http://www.classicspeakerpages.net/IP.Board/
The Classic Speakers site is for people who enjoy the old Boston Speakers such as Acoustic Research, and Advents, and would probably be in the best position to give you the information you need about restoring your AR-3s. Btw, many around here will try to get you to buy newer speakers, and in some ways I'm in agreement with their arguments. Nevertheless, there are many who enjoy collecting and restoring and listening to vintage audio equipment. Good luck in your restoration project.
http://www.classicspeakerpages.net/IP.Board/
The Classic Speakers site is for people who enjoy the old Boston Speakers such as Acoustic Research, and Advents, and would probably be in the best position to give you the information you need about restoring your AR-3s. Btw, many around here will try to get you to buy newer speakers, and in some ways I'm in agreement with their arguments. Nevertheless, there are many who enjoy collecting and restoring and listening to vintage audio equipment. Good luck in your restoration project.