Inside an owl's pellet

Using some very scientific equipment including mum's hairpin, a pokey thing from a manicure kit and a Henry VIII ruler I bought at Hampton Court Palace in London when I was 8 (With My Own Money), I began to dissect the owl pellet.

Owl pellets are basically little balls of undigestible bones, nails and fur that owls sick up rather than poo out. This one was found spat out on the grass under the owl box. Here it is before I started fiddling with it:

Here's a skull I found and a piece of vertebrae, I think:

Here are some claws, a rib and a bit of backbone:

Ok so obviously it's a small rodent, but there my knowledge runs out. Any suggestions anyone?