I have two tested good ones in stock and available for immediate sale.
There is a simplified way to use them, too: If your remote control head has two DB-25 connectors,
the HHCH can be plugged into one of them and the HHCH is set up and programmed as head unit B.
With this setup, you don't need the T cable.
In any event, my price is a fraction of the cost of a new one.
PM me if interested.
Elroy