Does anyone still make an outboard AC-3 RF Demodulator (1 Viewer)

Subject about says it all.

You might try Sony. I bought one on line from them about 18 months ago. I had to wait a while IIRC the phone rep told me they waited until they had a certain number of orders built up and ran a production run of them on one of their flexible assembly lines. This could be BS coming from a CSR after all but I have known other companies to do the same with other products with low demand but that all of the tooling has been long paid for. It has both a coax and toslink for maximum flexibility. I have mine laying in the back of my cabinet hooked to the switched outlet of my reciever (I knew I would find a use for them one day).
I tried to add the MOD-RF1 to my cart and kept getting timeouts. You might need to call them on something like this to accurate info though.

Your best bet is Ebay, and then the HTF hardware for sale section, and then some of the other audio-related marketplace sites.