How to merge 2 calendars in Outlook 2011 into one (successfully)

Hello,

What is the best way to merge two Calendars within Outlook 2011 for Mac?

I tried to do this earlier in the week, using the list method to drag all calendar items from a non-default calendar into the default calendar so that only the default calendar had any content and all was in one place.

So I then deleted the non-default calendar as it was showing as empty ... and I did this carefully ... yet Outlook DELETED BOTH CALENDARS.

So then I needed to recover from a Time Machine backup, only to discover the Database file is NOT STORED by Time Machine (astonishingly) and that I needed to Rebuild the Identity.

Rebuilding the Identify failed on Step 4 with a -180000 message (I can't remember now exactly) so this has sent life into a tailspin for 3 says all because I was trying to simplify my Calendars (I don't even know why I had 2 Calendars in the first place).

I also tried Exporting but then it ended up DOUBLING every entry in the calendars when I re-imported the .olm file

Any assistance will be greatly appreciated.

Thank you