changes do not appear in the merge

Dear Developers,
I have a question. I am merging two branches here
https://code.launchpad.net/~maddevelopers/mg5amcnlo/3.0.3-neworders/+merge/389779
but not all the changes appear in the diff.

This may likely be because I pushed some changes in the target branch which were not intended for it, and then undid them in a separate commit.
In particular, revs 964-968 here
https://bazaar.launchpad.net/~maddevelopers/mg5amcnlo/3.0.3/changes
should have not been pushed to that branch, rather to the development branch (3.0.3-neworders).
Hence, in rev 969 of https://bazaar.launchpad.net/~maddevelopers/mg5amcnlo/3.0.3/changes
 I undid these changes, but now it looks like 3.0.3 is ahead with respect to the
https://code.launchpad.net/~maddevelopers/mg5amcnlo/3.0.3-neworders/+merge/389779

How can I force to keep the changes in https://code.launchpad.net/~maddevelopers/mg5amcnlo/3.0.3-neworders/+merge/389779
?

Thanks a lot,

Marco