They seemed to. I don't know if this is normal but Seth would whine while chewing. I don't know if it's because he's used to gulping down the puppy mush we were feeding and now has to "work" for his food.
I gave them party wings, hit with a hammer a few times, and they chewed, chewed, and chewed some more and then swallowed them. They each ate 2 and then whined for more, but I did not give them more.
Continue guesstimating. Best way to feed raw. I have never weighed anything out.
I would suggest having 60 pounds be the target weight as adults. I would just continue what you're doing for now as long as they have normal bowel movements, good energy level, and no vomiting. Keep an eye on their body condition. If they look a bit pudgy, feed less and vice versa.