Originally Posted by
WizardOfBoz
If you want to try to get parts, first, note that there is no "split ring washer". The upper split ring is a bearing race, not a washer.
I believe that "split ring" is the conical compression ring that keeps the upper bearing cartridge centered on the steerer. It's not part of the bearing assembly. I agree the lower item is just a dust seal, probably rubber or plastic.
Neither part is going to be easy to source as replacement items and starting from scratch with a new headset is probably the best approach. Note the OP is in Spain and likely doesn't have access to many of our (USA) suppliers.