What David is holding, as you will see from the model designation, is a dCS 578TS, a lesser spotted dCS product from the pro era. To the best of my knowledge it is the only dCS product ever to sport a ”Panic Input”.
Questions:
I’ll try to think up a suitable prize… 
A dCS converter for the BBC radio centre in London. “Don’t Panic Mr Mainwaring, Don’t Panic” 
Redundant mains, clear status leds and a schematic diagram on the front because you don’t want your broadcast to stop mid-air. This is also where the panic input comes in I would think, so if somehow your front-end bitstream(s) /other shelf also double/redundant cease functioning you can still keep going. In a normal situation the panic input should never be necessary. Used maybe, but in anger I hope not.
The physical key is a very nice touch. I am intrigued by the monitor pinout, is that some sort of balanced headphone out socket?
As there are other shelves mentioned there must have been several made. I’m not sure if I visited the old BBC back in the day and anyway 2004 was later then when I was at dCS, but I did get to spend one day going to London and visiting Abbey Road with Robert I think it was who was the account manager back then.
Here’s my 972 and prototype built from old parts 955
