OO3 → Markdown → Scrivener > File > Import MultiMarkdown

may prove to be a shorter route than:

OO3 → Applescript → OPML → Scrivener > File > Open OPML

One route to the Markdown would be the MMD exporter for OO3

(http://forums.omnigroup.com/showthread.php?t=7625)

http://fletcherpenney.net/2011/10/omnioutliner_plugin

(FoldingText outlines will also import directly through the MMD importer, but you may not want the tab indentations).

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