What to do with the skin on the joint?

Oh, I am so jealous. Now you know why I called it a flavor bomb treasure. I'm equally as guilty of eating the crispy skin, hot out of the oven. But at least now you know how to use the skin to the best advantage, and what you could do with it after removal. I wish cuts here came with skin more often- but too many people are afraid enough of the fat, and the sight of pig skin might be more than they could handle.

Thank you both. I did as suggested and it was perfect.... including baking the skin which I must admit to eating while still hot. OMG! So bad but SO good!

If you have a bone-in shoulder with the skin intact- you've got a flavor bomb treasure. I lived in Suffolk for 7 years, and sooo miss my butcher shop there. That skin will help add collagen to the sauce, and a level of unctuousness you won't get otherwise. Leave it on for the 4 hours, and it will easily slip off the cut. You will need asbestos fingers to do this- otherwise use a kitchen towel. And tempting as it might be to toss the skin- known here in the States as the "rind"- don't do it. Cut it into smaller bite size bits and bake it in your oven until it renders and gets crispy. It makes a nice addition to a salad, can be eaten with various dips, or used in breads or such as a nice savory add in. You can also add it into broth for soups, use it to season veggies while cooking, or into a pot of dried beans.

Unless the whole thing is completely encased in skin, I think you'd still get the balsamic sauce in your meat. The other thing that might happen is after 4 hours in the slow cooker, the skin might be easy to pull off. Another option is to turn the setting on your slow cooker to a lower temperature and cook in the balsamic sauce for longer.