Martyn Hnatiuk has informed me that the Beetle shown in these photos is a Soldier Beetle (Cantharis rustica) and not the Tanbark Borer (Phymatodes testaceus) as I had initially claimed. I've decided to re-write this post since quite apart from being misleading the original post now makes no sense whatsoever.
A Soldier Beetle (Cantharis rustica)
I wasn't quite expecting a beetle of this size with 'long horns' to be anything other than a longhorn. No wonder I couldn't find a photo match of it online! This species is quite abundant and could possibly have been a feature of one of Martyn's posts on this blog last year and maybe one of mine (identified correctly).
Thanks for letting me know Martyn. We live and learn...and sometimes forget again!