I was beaten to the ID for the female Stag Beetle but you ought to drop a line to the
Wildlife Trust as they are quite endangered and I would have thought as rare as hen's teeth in Yorkshire.
I used to live in a Stag Beetle hot-spot in South London and they were an amazing sight as they flew about clumsily at dusk, buzzing like mini helicopters. The males are noticeably bigger (up to 70mm!) and have the full stag's horns. I once saw a female being courted by four males including a lot of the horn-to horn wrestling. They also use them to hold onto the female once they finish their jousts.
SharkeyP