In fact there is a funny thing about the bolts/screws - there are four matching ones and then one that is unique.
The label in the middle of the hole says "I'm the desk that you're sitting on" :lol:
I don't think the assembly is for a CD changer - its made up of two halves that are specifically matched in order to cradle something - see below.
Turns out the other piece is a standard Denso relay that is used for the blower, fuel pump, defroster etc.
Cheers, P.