I have a need to show a service contract that is being billed by % completion on each line item.  I'm doing this by making the service items fulfillable and using fulfillments for the % to complete.  However, as an item is fully billed, it's dropping off the invoice that is generated in the following period.  I'd like to have all line items on the sales order show up on the invoice regardless of status.  I've checked the show unfulfilled items, that works great.  My issue is in the fulfilled items showing up.  Is this just something I can do