That depends. The four tail light mounting holes suggest either a UK or USA bracket. Other export market K6 models used a two hole tail light mounting bracket. The original finish is black for the UK and chrome for the USA.
BryanJ is correct, both brackets will bolt right up. No modifications needed.
A correct UK restoration will have a tail light lens without the side markers, I got mine from David Silver (UK)
Tip: Include which K6 market model you have in your signature for future replies.