O'Grady wins this one, probably by decision. It's a shame that we don't hear anything about Harry Arroyo. He was a good little fighter whom had a really good career. Unfortunately most folks on the site only remember O'Grady for his Tuesday Night Fights shenannigans and not for the quality fighter he was.
Good fight, O'Grady has a little too much experience for Harry. Arroyo was good, but he wouldn't have the answers for the seasoned O'Grady. Sean by UD.
Sean would have a few close moments early, but his experience kicks in around the sixth and enables him to take a UD in 15 over Harry.
And he sure was a quality fighter. SRR was so impressed, he uttered that "this kid fights like a black"...and in winning over Shig Fukuyama with that horrible cut that he had, he was described as a "small Carlos Monzon" in the way that he stayed calm and battered his way to a stoppage win.
I saw Sean fight in some of the Hotel "smokers" in OKCity back in the late 70's. It was usually Sean vs some Mexican with a 20-38-2 record....who was tough early, but got TKO'ed late in the fight. But Sean got a lot of experience when he was quite young. His Dad Pat, out in LA, threw him in with Danny "LiL Red" Lopez when Sean was still a growing Bantamweight and Lopez was a full-fledged Feather and Lopez won easily.