In the 1980's omas restyled its lines of pens. Top of the line was the big paragon flanked by the 557 ogiva.The imprint on the barrel of ogivas were originally omas 557/s (matching the imprint on paragons which was 557/f) and later on it became omas extra. Very early ogivas (557/s) an paragons (557/f) had a serial number imprinted on the barrel. The digits were simply a way to keep track of production and were soon dismissed. Like paragons, ogivas were fitted with two tone nibs.