A short while observing from a distance was rewarded by seeing and photographing a Blue Tit visit the nestbox this morning.
Friday: Lots of activity with several short solo visits to the box.
Saturday: Didn't see any evidence of any visits.
Sunday: Another shuffle session and then I spotted both birds in the box at the same time for a brief period.
Today: Another shuffle session spotted. Lots of brief visits.
Activity and interest seems to be gathering momentum.