I remember the Magra 531 from BITD.
I used to live near Guisborough till `84, and rode Margrove Park quite often, along with Saltburn and Redcar tracks. There was a lad that lived round the corner had a black Magra 531 which really stood out from the crowd, all I really know is, they were a limited run of frames sold through Tuckers and they were reputedly `kin rare and expensive.
Has anyone got any pics they can post?