Disputes like this at the very least becomes very costly for both parties, notwithstanding the fact the damage each one may inflict in just trying to get the upper hand over the other.
Considering that you've brokered into an agreement before, haven't you explored the possibility of just resolving this amicably, with both parties finding a common ground to ensure a win-win situation for both.
Going through the lawyers and courts should be the last resort. I know to some degree this advice (which you could take with a grain of salt) may not hold some ground with the others. But just the same, you've worked together before and there should be no reason for you not to be able to settle things properly.
Considering that you've brokered into an agreement before, haven't you explored the possibility of just resolving this amicably, with both parties finding a common ground to ensure a win-win situation for both.
Going through the lawyers and courts should be the last resort. I know to some degree this advice (which you could take with a grain of salt) may not hold some ground with the others. But just the same, you've worked together before and there should be no reason for you not to be able to settle things properly.