Well not 100% solved, but worked around.....
I move the various documents to chunks and the inheriting & selecting works properly. I would have preferred to use normal documents to make it easier for others to edit these notifications in the document tree using the RTE, but oh well.
None== ||Summer Shutdown=={{SummerShutdown}}||Winter Shutdown=={{WinterShutdown}}||Trade Show=={{TradeShow}}||Inherit from parent doc==@INHERIT||Another Test==Some basic text
