
Sorry, im not in the essex area, but have you tried using the AMP frozen meats? You can get them at Pets at Home stores...
As far as butchers go, keep looking, go for the small village type jobs, the posh ones, as they really butcher their own stuff, rather than just buy in prepackaged stuff......when they butcher themselves, ther will be left overs, which u can usually score for FREE!!!
I can get massive sacks full of lamb ribs, beef ribs, lamb shanks, chicken carcasses ....all sorts of gory stuff, from my local butcher. But, it took me ages of going round butchers explaining what parts i needed, what i couldnt use etc etc......also if you do find one, ask them really nicely if they will cut stuff up smaller for you, u have NO idea how hard it is to seperate out lamb ribs in to 2's and 3's if you have only got kitchen scissors and ablunt knife (u need a hatchet or a power saw or a really sharp hacksaw).
Goood luck
Em