Thanks for all your suggestions. (Sorry it's taking me a while to get round to reading all of them).
I wish I could find something to keep my dad occupied. He was always a very active, intelligent person who kept himself busy with work- he was a commercial traveller and went all over the country when still working. Even when he retired he set up a little business making things- he's a gifted artist, and read and listened to music all the time, as well as cooking and doing various bits of DIY on our house. (I did try and attach an image of one of his figures but can't figure how to shrink it down to size.)
Now, however, he has little or no interest in any of the things he used to love. I know he is bored, when I am at work he spends much of his time out and about talking to people. However, I have tried, repeatedly to get him interested in books, listening to music and making things but he just won't, He'll get all excited for a day or two, may even make a small effort to take part, but it doesn't last. He tells me the books are boring, tells me he doesn't like the music (or it's mine and he doesn't know why its on), and as for making things, he doesn't think he's good enough, his hands aren't steady enough, any excuse. I've told him it doesn't matter, it's just for him, and in fact the one thing he did draw was still good, but he won't have it. The only times I can get him actively involved with things is helping me do housework (and today he's been helping me with the DIY as opposed to how it used to be- the other way round). He does at these time seem much more like himself, but of course when I'm not there, or not able to find things to keep him busy...
I've also found he gets worked up over any kind of appointment or set time when something may happen. Even the days he goes to day care, the night before he is more anxious, asks more questions. On one occasion when my brother mentioned he might visit it was terrible. And no matter how many times I answer him, and reassure him that he doesn't need to get anxious it makes no difference.
I'd love someone to say to me: "Here's some brilliant ideas to keep him occupied, and this will prevent him getting anxious," because nothing I've tried works.