Sadly these are 2-10 years old and we've been refining our COA over the years, with a major revamp this January.  I find strange that quickbooks wouldn't provide a way to export all your "current" accounts since these are the ones you actually use (or plan to use).  Is my situation unique in some way?  I watched bunch of videos on consolidation of QBO companies and they all do the same painstaking insertion of missing accounts to get everything to line up.  

The workaround I've discovered its to start off the year by adding a zero balance transaction into each account in order to force QBO to show the account as part of the "Active" accounts.  It's tedious, but you only do it once and and after that you can generate full PNL's and consolidate with almost a single cut and paste.  I think I'll go that route.  

Thanks for the help.