Would you do me a kindness Dave please, and photograph the parts and post them here? My replacement headset, which came direct from Across (paid by CRC), does not have any extra parts, such that you describe.if you ask wiggle/crc nicely, as I did, and point out its a known issue, they should send you the kit. I just said mine is now feeling the effects of this issue, starting to notch, please send me a replacement and I will fit them (easy job for me, I am was a Motorcycle mechanic).
BTW I had my bike from Wiggle, they have been great so far, very pleased with them.
(I am aware crc are just another name for the same company)