C'est la vie, it goes to show you never can tell170 for four hours? In chess, they'd say "(?!!)" If 170C (338F), way too hot to be "low and slow," and get the proteins to denature, which was the idea. If 170F, too cool for safety, and four hours isn't nearly enough time for the proteins to completely denature. That "denature" thing is what makes slow cooked food so tender.
What happened to "250 for 7 hours?" "250 at 7 hours" are time and temperature directions, not a metaphor. I suppose the fault is partially mine if I didn't specify F or C, but still... You said you'd looked up "with a spoon" recipes and didn't ask for anything more specific.
I'm afraid the cut is going to be more "lamby" than the leg because -- well, because that's just how meat shoulders are. And to be honest, a low and slow approach brings out meat's natural flavor. But low and slow weren't in it, were they? Still, considering that the meat should have cooked tightly wrapped or covered (you did cover it, right?) with a substantial hit of wine in the bottom of the pan, you've got a pretty good idea of what a braise is like.
If you just stuck it in the oven and roasted it to medium-well, I can imagine that it was pretty tough, somewhat greasy and more than a bit gamy. Most parts of a lamb should be cooked to medium-rare or very well. Anything in between is anathema. The shoulder particularly responds much better to overcooking.
Finally, a lamb shoulder cannot be "carved," at least not in any normal use of the term. The bone structure around the ball joint is too complicated to take slices. You can "bone it out," if you like. The way to to this is to locate the arm bone, and run a very sharp boning knife along it so the tip just touches the bone. Then work the knife a little deeper into the meat, angling it so the tip follows the contour of the bone. Keep working along the bone until you've got its full width exposed. Trace the side of bone with your knife tip until you hit an obstruction and angle your knife to work around the obstruction. Expose each bone you come to, then work around it. When the structure is exposed, you'll have to work underneath the bones in the same way. Start with a very sharp knife; keep the knife sharp during the process -- it may need to be steeled a couple of times; make short, shallow cuts; and, be very patient. Once the shoulder's been boned, it can be rolled, tied, and treated like any other roast. This takes a while, which is why butchers don't usually do it.
It's also why a shoulder should be cooked long enough to more or less fall of the bone, or be taken with a spoon. So you don't have to "carve."
Hope this clarifies.
Sorry it didn't work out better for you,