The safest way I can think of doing this is with duplicate + merge, which will also retain the original snapshot timestamp, if that is important (doesn’t sound like it in this case, but for future readers who might). The idea is very simple: have a snapshot in an otherwise empty file, select it and the main document and merge them together:
- Duplicate the document with the snapshot you wish to copy into the other document. (Optional: only necessary if we want to retain the document the snapshot comes from; if it only exists to be “ported” into something else as a snapshot then we don’t need to duplicate it.)
- In the Snapshot pane for the duplicate, delete all unwanted snapshots and delete all text in the main editor. Likewise strip out all meta-data you do not want merged. keywords, references, notes, synopsis, custom meta-data. The idea here is to have a stub file that has no content but the snapshot(s) we want to “import” into another document.
- Move, if necessary, the duplicated document somewhere below the document you wish to copy to, in terms of binder order (nesting irrelevant). Merging uses the first document, in binder order as the primary, elements such as title will be discarded from the secondary.
- Select both the duplicate and the document you wish to copy to, and hit Merge (Shift-Cmd-M) or Documents/Merge.