UK OSGB36 projection

[jimbok8]

As with other posters I am having trouble with UK shapefile data.
Whilst the data imports correctly there is clearly a problem with the datum, as everything is shifted.
The source of the shapefile data is the UK Ordnance Survey (it is their 'Open Data'); I am confident that they know what they are doing.
Please can you help point me in the right direction to try and solve this.

PS Thanks for the excellent demo, http://leaflet.calvinmetcalf.com, very impressive.
Jim

[calvinmetcalf]

so the actual projection is done by proj4js if you could post the contents of the .prj file and ideally also where to find the the shapefile that would be very helpful