Picked up one in nearly new condition from GTVince based in Birmingham. Hes always breaking GTVs and 75s. Found a 75 he was breaking on ebay just messaged him and had it delivered in 3 days. Have been looking for over 2 years. So glad I got it cause the metal back plate on mine had totally perished.
Good luck in finding a new one.
Not ideal because they both have some screws missing from the back-plate. If your really stuck im sure the metal back plate could be removed and then bond the reflector onto the boot lid. Not ideal but could be an option