Ive got nothing...My knowledge of Brown is severely lacking. Not to many I pick over a prime Harada though..Al would have to be as good as his reputation suggests to get past him.
From the small amount of footage I've seen of Brown, I think a fast pressure fighter who could get inside and work his body with a constant punch flow is the type of fighter who would beat him. Harada fits that pretty well.
I do think that Brown has a good style for this one, that waiting and countering. But the dynamo that is Harada would likely keep going with that rapid handed pressure to get a decision. For me Brown is the greater bantam though.
Panama was 6' tall.... Harada, even at Featherweight would open his ribs and waistline with pure agresssive punching. I can not see more than 7 rounds of intense pounding, all in Harada's favour. Harada kept the best boxer/punchers of the era, on the back foot or circling to gain a points advantage. 'Panama', IMO would see an very early barrage of 'soreness'.... more than enough to keep him in bed for a week.