David. J. Hayes says "1M13 was the 12.10pm to Birkenhead. The Western will work it as far as Wolverhampton Low Level and return to London with 1A91, the 3.25pm WLL - Paddington. It is seen coming off the former GWR alignment from Birmingham Snow Hill and joining what was once the former Oxford Worcester & Wolverhampton Railway (OWWR) route to WLL. The OWWR entered the Black Country region of the West Midlands at Stourbridge and reached WLL via Brierley Hill, Dudley, Tipton and Bilston. Wolverhampton was the northern most limit of the GWR's broad gauge empire. I believe it reached Wolverhampton as a mixed gauged route (i.e. built to both broad and standard gauge specification). "