[p4] Fixing a release branch

[Vander Werf, Bruce]

We branched our main codeline as a release branch, only to realize that
we had included changes made since the point of release. I would like to
do this again at an earlier point (changelist), but I'm not sure the
best way to do this.
 
I can obliterate the bad branch, but I am worried about side effects.
When I tested this, the report was 'Would delete 594 client 594
integration 297 revision records.' There have been no revisions to the
branch, so I'm concerned about what this actually deleting.
 
I tried deleting the bad branch. When I tried then to renintegrate at
the proper point, it simply returned: 
 
    //depot/blah/blah/... at 896 - all revision(s) already integrated.

 
What's the best solution here?