Hi Paul,
I can see what Danny is trying to say albeit going off point but I agree and disagree somewhat LOL!
From info I have gleaned from my UK butcher pals they buy their briskets in vac packs in 20KG boxes where almost all of the fat has been trimmed. They further trim off any remaining fat plus any connective tissue from the flat and roll it as its very unattractive as a oblong lump of meat. It sells around £6 to £8 per KG and in their eyes and that of the housewife lean neat sells, fat does not!
It is probably going to be used as a pot roast for the housewife but I buy that same flat trimmed brisket for making pastrami or salt beef (corned Beef), where fat is unwanted. Now my pal is telling me that he can buy in Silverside cheaper than Brisket now. Its the same with pork, its more expensive for ribs and belly than for other cuts. Makro are selling Australian silverside @ £5.86per KG!
In the US they know fat is flavour therefore the more of it the better (think Kobe Wagu) therefore they are happy to have meat with loads of fat, hence the "packer cut". This starts out with the brisket on the bone including the plate. The plate is cut off and the rib bones removed including the curved breast bone. It is then "packed" without much trimming, which is what you buy a "packer cut".
Now I agree with Danny that USDA meat is totally different especially their grading (and taste), Black Angus, Prime, Choice and Select and even standard grades. This grading is all based on "Fat Marbling" with black angus and prime being more abundant and standard devoid of fat. Invariably all that we buy is standard to select as the "UK wants lean Meat". Where I disagree is to get the better cuts (select and choice) like in the US we have to get local butchers to cut from the bone. Now as most don't, this is why the likes of T & G, Hixons and Matthews thrive with on line supplies as they are big enough to hold meat on the bone in greater quantities than your local butcher.
Now if you think that the "UK Packer cuts" that are now being sold to us with fat intact, the savvy online butchers are now getting paid £8 to £10 per KG for his waste trimmings too.
So the key is buy big, buy on the bone and get it cut to your spec