One brand new, never used, Defender rear door tire mount stud plate.
Bought from RN about 6 years ago and just found it in the garage! Don't need it. This one:
Product Details - Rovers North - Classic Land Rover Parts
Not sure why the have it re-coded or listed by another number for $499. I paid $128 (plus tax, S/H). Yours for $100 plus shipping (I'm going to guess about $10).