With a Cardiff express

On my way from Leigh to Crewe for a day's photography on 30th . May , 1956 I have stopped for a while at Manchester London Road , recording on film this rather nice image of Longsight's Caprotti valved 44741 all ready to leave on a South Wales working , with a Western Region coach leading the formation.
I am not sure whether 44741 will work just to Crewe , or , more likely , run down to Shrewsbury from where this working will be taken onwards by a Western Region engine , Shrewsbury being the " Hand Over " point between Midland and Western Region locomotives in both directions on these North to West duties .
The massive elevated and almost windowless building with its strange looking gantry is the LNER (ex GC) signal box controlling their portion of the station.