Rail gauge from British Rail

Rail gauge, wear, for British Rail 98 and 109Ib flat-bottomed rail, caliper gauge for rail height, calibrated in Ibs, 78.9 (1.6/1.7) 98.0 and 89.8 (1.7) 109, and in inches, 4 1/2 (1/16) 6 1/4, steel, marked 'E. Labrum'.