So here's the next development - having realised the similarity to Minories, it is now a Minories with sidings.  This one addresses the issue of the headshunt not being accessible from the inbound route.  The right-hand part with the fiddle yard is unchanged from the initial plan.

A variant I tried when drawing this is to have only a single siding to the bridge, which then becomes a headshunt to two splayed sidings in the top-left-hand corner.  This arrangement might be better for goods and/or simmering engines awaiting turns.

Any more thoughts anyone?