I've had another look at my OEM airbox and the AFE one. The problem with fabricating this system de novo ourselves, or modifying the OEM system lies with the way the MAF connects to the induction system. I don't think there's sufficient scope to modify the OEM airbox where the MAF attaches the induction system is already flaring out to form the body of the airbox. Creating a connection with MAF input (like the highly chromed ring on the AFE system) would be much more difficult than creating a new airbox to surround a cone filter.
M@r]{, can your mate fabricate an adapter ring that allows a cone filter to be connected to the oem induction system with a MAF input port?