I remember the component facing of the equipment in my friend's parents' house to be something like leather(!) in oxblood stain. You'd also have to press and hold the power button to shut if off.
Some of the remote "phone pads" were built into what looked like a Tiffany's jewelry gift box which would set on a desk; others were built into the walls.
Keep in mind, high price when new does not necessarily translate into desirability on the secondary market. To put it bluntly, these systems were made for people with far more money than sense when it came to matters of hi fi: For the same money, the wealthy people who purchased Boulton (as likely due as a social connection with Mr Boulton himself as anything else) could have purchased some truly fine, high end audio equipment that is highly collectable & desirable today.
(The above scenario squares perfectly with the type of people my friend's parents were).
Frankly, I see John Boulton gear going nowhere fast in the market of vintage hi fi. It's so obscure that few (even in the hi fi world) even heard of it and if operational specs are so completely incompatible with industry standards as Dave & Bowtie suggest, it would seem to make matters all the worse.
If dirt cheap & you have no better use for the money, by all means buy it - but bear in mind it will probably never have future value beyond that as a curiosity piece.