I recently acquired this
http://imgur.com/a/UF5YO I don't know if anyone is interested but I thought there may be some PC Engine related historical interest. The photos explain it all really (grubby).
I think it has been left unused in someones loft/garage/garden shed for quite some time. The power supply is enormous and has caused a bulge in the box lid and the pins protrude through the polystyrene.
Its not a proper conversion as it requires the TV Booster to connect it to a TV. I have tried to tune it in but have had no luck as I don't know whether the TV booster requires a separate power supply or gets power from the ext bus (I used to have a grey TV Booster which didn't have a power socket).
The ground panel has been replaced with just a wire connecting the 2 grounds and two traces have been cut (analogue ground and the other I think is related to the RF unit) and there are wires connecting resistors to pins on the ext bus.