Browsing through ebay and saw this, a semi broken RD64.$_12.JPG

Which piqued my interest in that, if the control unit is simply attached as an er bolted on bit...(as it is coming off)

Then how far does the PCB inside go under the key bed?. Is it separate?

In that if it doesn't, then I see some possibilities here, whereby the control unit wires/cables can be cut and soldered/crimped into stereo jack connectors. So that it becomes detachable, making it MUCH more manageable and portable.

Just waffling some thoughts of course... as I could never take a saw to a piano (my Danemann did not fit through my 28 inch doors being 32 inches wide and had to be taken round the side).
I want to be so good at Piano like VK, that Roland gives me a free piano too!