Cool pictures! How close were you? Man are they ugly / goofy looking though in super short summer hair. Oddly, I dislike mounts of super long shaggy goats as well, when mounted that longer hair it mat's easier and looks all streaky and unnatural to me. I like the mid-length hair. My wife shot her goat early season on the Beaver, it was haired up pretty good for that time of year: big beard, long chaps, long hair on the back and brisket... a little shorter on the sides but I think that will make it look better mounted (IMO), judging from mounted goat picture's I've seen on the net.
Anywho as for judging... it can be notoriously difficult. I spent MONTHS looking over goat pictures, harvest pictures, scores, online quizzes and whatnot for my wifes hunt last year. Big tall nannys are easy to discern, its the younger nannys that can be mistaken for a billy. For billy's, you are splitting hairs on score / age. A single year different goat might only have 1/4" difference or less in horn length. If you can get close enough with good optics you MIGHT be able to count growth rings. Older billys will have a more boxy face, thicker nose etc.
Here is some useful info:
http://www.adfg.alaska.gov/static/hunting/goathunting/pdfs/goat_long_quiz_for_web.pdf
http://cpw.state.co.us/Documents/Hunting/HunterEd/MountainGoatIDQuizWEBRev09102010.pdf
Packout gave me probably the best overall advice going into the hunt: "Just have fun and dont sweat the score." Its way better to get something nice in a easy to access area vs something you nearly kill yourself to get into, and to get it out of.
One final thing... don't get all hung up wanting to hunt a specific goat, don't forget you wont be the only one up there hunting the same herd.
-DallanC