Beacon Mixer Valve-Where to buy?

Does anybody know where I could purchase a Beacon Mixer Valve? I found the company's website and they are located in Massachusetts where I live but it appears they no longer exist at that location. All the phone lines are disconnected with no forwarding #. I have a 3/4" Beacon 69 Mixer on my furnace and it no longer adjusts (rusted).
Thanks in advance,
Ron

Here is their website where I got the info:
http://www.beaconvalves.com/IEindex.html