Sales order not billed, a portion of revenue has already been recognized - Enter complete SO into new sub, recognize and reverse the revenue already recognized so you do not over recognize revenue, this amount should already be recorded in the trial balance you are importing for subsidiary balances. Most importantly you should test these scenarios in sandbox beforehand, there will be nuances to work through (You are using projects, understanding GL impact of Cash Sales, etc.) that you'll want to be sure the business understands fore doing this in production