After another 40 miles, the car continued to drive well but
@DSM10000 the CEL has now come on. The codes are P2009 (Intake manifold air control actuator) and P0101 (MAF/VAF - range/performance problem). Fuse 104 remains intact, but haven't tried reconnecting the EGR yet - got too dark! Will do that one tomorrow.
My thoughts are that i may have the swirl motor problem too, which can be "fixed" with a resistor. More annoyingly, P0101 means that the MAF sensor i just fitted hasn't worked.
Hope there is some other interpretation!!