It did not take long for a bluetit to come and investigate what I had been up to. Box1 was remounted yesterday and today it has a visitor.
Not only did he have a look at the box, but he also went inside! I hope this is a good sign for the future.
I have also managed to clean out Box2, and check all the lights are working OK. Apart from a piece of moss that must have been hiding beneath the camera when I remounted it, it looks good. There have been no visitors to it yet though.