I just don't like blood unless it comes from raw wild game. All other blood, even from grassfed meats, tastes inferior to me.
Forget about getting adrenals. I tried that for years, with no luck, the farmers just look stupidly at me, and I suspect that the adrenals are automatically removed with the spinal cord and brain at slaughter. I can get raw pigs' brains(only after asking a hundred farmers or more), but since pigs are almost always fed on 100 percent grain diets, that's a waste of time, IMO.
From a few select grassfed meat farmers, I was able to get hold of raw grassfed sweetbreads(ie thymus/pancreas) quite easily. You just need to keep asking/searching around at grassfed meat sites etc.Not that I consider them to be that useful, nutritionally, given my own experience.
I found raw grassfed lung irritatingly difficult to chew, and had to spend some minutes chewing each mouthful before swallowing. It's just cartilage, IMO, and therefore a waste of time. Some here disagree with me, though, it seems.
I think(?) I got raw spleen once(dark reddish slightly cylindrical small organ?) but the farmer could not confirm what it was.
From my raw wild game carcasses(raw wild mallard duck and raw wild hares) I can't get the head(presumably shot off etc.) but I can get the raw kidney/heart/liver/blood. Also some unidentifiable black stuff from the gut which I happily eat.
Abroad, I am able to get hold of raw blood in plastic containers minus any accompanying flesh. Maybe a wild game butcher might be able to supply you with such, if you ask around.
Re abattoirs:- I have had this problem all the time. Most farmers just dump their animals at abattoirs as it's easy for thm that way. Also, because of the retarded hysteria after the BSE crisis, the UK government (apparently) forced many abattoirs to close, thus forcing farmers to drive their animals from even farther away. I get far more success, as a result, with those farmers who still have their own abattoirs and do their own slaughtering. Trouble is, even those farmers usually just throw away their organ-meats - this is apparently because current UK law forces farmers to have their meats inspected twice after slaughter - once by UK-government inspectors and secondly by EU-appointed vets from abroad(usually Spain). Since the farmers have to pay for the inspection-costs involved, they are somewhat reluctant to have them stay around long enough to deal with organ-meats as well. Plus organ-meats are much cheaper than muscle-meats so the farmers don't get enough profit from them - it's a hassle to cut up bones for raw marrow, for example, when raw marrow typically costs just one pound fifty pence a kilo including the weight of the bone.