While I wait for the correct empennage fairing to arrive from Vans (they sent me the wrong one by mistake) I thought I may as well go ahead and fit all the necessary nutplates that hold it on. Nothing difficult about this, just chipping away at some simple jobs until the fairing arrives.
I fitted nutplates along the top inboard ends of the horizontal stabiliser, and also along both bottom edges of the vertical. All exactly as per the plans.