FAG NJ203E.TVP2

Just bought the above layshaft bearing and have been looking at the same bearing with an additional C3 stamping. The bearing I have necessitates the removal of the inner race to fit, which means the layshaft runs on the rollers, is this correct

No,
the layshaft runs on the inner race not on the rollers with the shoulder of the race pointing outward towards the layshaft.
Sure you got the right size bearing?

All good, just another stupid mistake!!