When I went to the Trans Lancs Historic Vehicle Rallies at Heaton Park, Manchester in the 1980s & 90s there were usually one or two lorries present bearing the name 'W H Bowker Ltd'. 1998 was no exception and here's a photograph I took at the rally in September of that year.
There's little information in the programme of the event about these lorries, other than that they were both entered in the rally by C J Gardner of Oswaldtwistle, Lancs. The one on the left is a 1967 Atkinson Silver Knight with a Gardner 6LXB diesel engine of 10½ litres producing 180hp. The lorry on the right is a 1934 Leyland Beaver TSC9.