It was 1974 when WCML electrification to Glasgow was completed and the "Royal Scot" electric locomotives (87s) were introduced. I think that in 1964, 47s started appearing at Paddington on through trains from Snow Hill, Birkenhead etc because the London Midland region took over Birmingham's ex GWR lines in 1963 and the westerns were moved to the western region's other lines. I don't think the Birkenhead/ Wolverhampton/ Snow Hill services to Paddington changed locos en route? Either way, they had ceased by 1967.
They did at Chester! (Train reversed)