I don't know why you would lose "1/2" a shoulder. Just cut around the exit wound. Then when you bone out the meat, remove the sinew and white tissue that connects the muscles, and wash and rub out the congealed blood under them. Soak the meat in cold water with some salt in it to draw out more blood. Change the water, and salt a couple of times over several hours. The meat will turn a more pink color like you see with pork you buy at the grocery store, rather than the dark purple you see in venison. Removing the blood helps the flavor of the meat.
I cut the smaller muscles in the forelegs into one inch chunks, to use for stews, or chili.
I do cut away all the white tissues, however, as they contain enzymes not present in beef, that will toughen the venison, even during freezer storage, and also make the meat bitter tasting. Its a bit of work, but with sharp knives, it goes fairly fast. The meat left over is going to be tender, and taste very good. I have had many people ask me what meat I put in my chili, or in my Stroganoff, and were surprised that venison could taste so good, much less be so tender. Unless I feel bits of lead in the meat I cut away from the primary wound channel, I throw it in to my scrap bowl, and grind it up for venison burger, which I use to make Sausage, instead. See my sausage recipe on this forum, down towards the bottom of the index page. If there are bits of lead, I toss the meat away. :surrender: :hmm: