When you say ball lock is that's just your standard corny ?
They look like this note these aren't the actual kegs
Haha oh yeah! there defiantly ball lock i don't think Ive ever seen the pin lock ones before and the seals on them all are fine Ive replaced both post seals in and out and lid within the last 6 months.By ball lock I mean the posts lock with the ball bearing mechanism.... Pin lock posts need to push down and twist to lock into two pins but the ball lock you pull up the connection and slide it over the post (very poor explaination, I know!)
Also, do you think the kegs need a seal replacement? or are they in working condition, ie you have used them in your system without leaks? If so I'll actually take two