Here are a couple from the Railway Mags, I have no connection with either:
www.nigelbirdbooks.co.uk Tel: 01974 821281
Nick Tozer:
www.railwaybook.com email:
nick@railwaybook.com tel:01484 518159 (answer phone). 155 Church Street, Paddock, Huddersfield, West Yorkshire, HD1 4UJ.
Another possibility is to go to larger Model Railway Exhibitions. Take a sample list and talk to any of the people on the book stands. Nick Tozer may be at Nottingham Model Railway Exhibition this weekend.
Hope this helps.
Best wishes,
John H-T.
Just checked the Nottingham Model Railway Exhibition web site and Nick Tozer is not listed but another possibility: Bill Hudson is:
http://www.billhudsontransportbooks.co.uk/