The simplest solution is:

    # try the merge; you'll get conflicts on those files
    git merge topic

    # discard the versions from the topic branch;
    # you know you already merged those changes in
    # the funny "git checkout commit", so any differences
    # are due to changes on master.
    git checkout --ours new-file-{1,18}

    # now you are free to fix up any real conflicts
    # and resolve the merge
    git commit

This has the advantage of representing the true history. You had two lines of development (the original topic, and the "squashed" history created for deployment), and the merge shows them coming together and choosing the deployment-side content.