I used some Kiwi made, lathe-turned MH cases back in the early 1980s. Excellent for blank-fire work but tended to fracture after a few stiff loads in the old Mk3 Martini.
BELL in the US used to make a ".577 Basic" case that was a proper drawn brass job you could make into a variety of old British cartridges. Expensive but apparently they last fairly well. Sadly, they sold the business to PMC, who have never continued the production of the "odd-balls". I suspect that PMC wanted Bells production technology, not a boutique product line.
RCBS were supposed to be doing something along this line a while back; any news?
I had some Epps turned cases for my 577 at one point. They worked well but after 10 shots the first one cracked. They cost $5 per cartridge and expanded just like all others did. The crack was just at the mouth and they had to be sized there for bullet retention. I was shooting a Snider 2 band. I used paper patch and Pyrodex. These sound like a fantastic idea because they probably won't expand much to begin with and likely won't crack during use. Good looking ammo.