Sorry to ask such a mundane question but I could use some help. Have a Pog frame and looking for a bottom bracket to fit. Its 70 mm (69.5) BB shell width and 126 rear dropout spacing. Will be useing an old pre '74 NR crankset. Can someone confirm the size I will need for this and if any one has a spare they would like to let go in very good or better condition - I would be interested. Would prefer Campy.