Yes, Albion in all its 1:250,000 glory, brought to you by the British taxpayer ;)
I downloaded the images from here (1:250,000 Scale Colour Raster), then embedded them in a large LaTeX document using pdfLaTeX. Right-click on the images and choose Save target as…, if you don’t want your web browser to open it. The download might take a while to start. Let me know if you have issues.
London-Birmingham area (PDF, 35 MB, A0 paper, 841 x 1189 mm)
Central Scotland (PDF, 19 MB, A0 paper, 841 x 1189 mm)
Great Britain (PDF, 94 MB, should be printed on a huge format -at least 2 x 2.82 m- or else placenames won’t be readable)