Hello Peter, I am Keith, and pleased to be able to help you with your question.
I would tend to rely on John Arther Day and Jane Dalgety providing the facts in this case are on all fours with theirs on this matter. The expenditure would then fall within an improvement under the CGT regime. I must say I am surprised that HMRC did not appeal against the decision!
I do hope that you find my reply of assistance.
Thank you for your support.
No Peter, I think it strengthens as to opposed to weakening your case.
Delighted to have been of assistance.