To be honest the Enfields are not normally up to much but quality stuff (like the No8 at the recent auction) always fetch top dollar.
My own feeling is that most of the guns tend to end up there as they are not up to scratch to sell privately. (Always the odd exception of course)
You can pick up any one of dozens of 12 bores for £2.00 (example Coey or tatty, loose actioned Spanish)), .22rf for £20 but quality does fetch money.
Sorry - dont know of any 'Midlands' auction houses - try a google search ?