Thanks Tony.
I'll have to tear her apart this weekend and remove all the bits that aren't stock.
On reflection my comment was perhaps a little more harsh than I intended. But it would seem that the original builder had not decided whether the carbs were going to be "suck through" or "blow through" and in any event there is no sign of any pipe work or trunking to effect either way of fitment.
Then there is the same problem that unless my aged eyes and the camera angle have defeated me, those two turbos are not a matched set - that means they will wind up at different rates and most probably have different mass flow capabilities, a problem that does not auger well for balancing the output of the cylinders.
The position of what I assume are oil collectors under the turbos is going to place serious restriction on lean angle, and as oil, like water, will not flow uphill I wonder how it was envisaged that the oil would return to the sump.