"Musica" Home sound distribution unit

"Musica"   Our home is wired for sound throughout.  The audio distribution to rooms is by a NetStreams Musica MU 5066.  4 source inputs; 6 rooms outputs.  The unit was installed about 12 years ago, and has worked just fine till recently.  One (of the 4) source inputs has failed, apparently a short.  Luckily the other 3 work.  But, really need 4 to use the feature of distinct source inputs can be linked independently to any of the room outputs, if kept separate inputs.  Am searching for someone, somewhere may have one of these (Musica MU 5066), either new still sitting on a shelf, or in nice working condition used.

The company was based in Austin, TX and was purchased about 10 years ago, and the new company chose not to support this line any longer, and does not offer factory service.  Perhaps there is a keen audio service shop one could recommend to troubleshoot and repair this unit?   Appreciate some guidance or keen leads.    Thx