Chuck, how many records are we talking about? In the end, what is simplest for the client and how much are they willing to spend? Changing the field is doable, just a royal PITA which as Myron points out, you may not recover your investment. But if the customer is a great customer which you want to help, by all means, grab a copy of their files and give it a shot. Don't forget to change the SO open order detail and possibly the SO history detail.