My second pear variety caused Jim a little further deliberation as reference books were consulted and samples were cut open. He soon identified it as a late pear - which sounds about right given that they've always been hard, even when they're falling off the tree. A few more comparisons later and we had a name - Winter Nelis. A variety with its origins in Belgium in the early 1800s, it's a small squat fruit, heavy with russet and not particularly attractive (a pear only a mother could love). But armed with Jim's advice, I shall be harvesting them at the end of October, putting them into storage and then enjoying beautifully ripe pears at Christmas.
Now, can anyone lend me a dozen apple storage trays??