Can the Ordnance Survey national grid reference system be used or laid over OpenStreetMap maps legally, and if so how? Could I then print it out, ideally to a scale that I could use a romer (the measuring scale on some compasses) on, and allow map and compass navigation?

I would like to know if Can the ordnance survey Ordnance Survey national grid reference system could be used or put laid over openstreetmap legally OpenStreetMap maps legally, and if so how, could i how? Could I then print it out out, ideally to a scale that i I could use a roamer on, thats the romer (the measuring scale as on some compasses,so that compasses) on, and allow map and compass navigation could be done. thanks andy navigation?

I would like to know if the ordnance survey grid system could be used or put over openstreetmap legally and if so how, could i then print it out ideally to a scale that i could use a roamer on, thats the measuring scale as on some compasses,so that map and compass navigation could be done. thanks andy