Lyndon:
When Softrak does a database repair of this type you want to be very careful to ensure that the accounting implications are considered.
As the latest GL version is brand new I haven't tried this yet but it allows you to post transactions to any prior period. I'm thinking that it could be used to correct this problem. Some careful planning will be required and you would want to test it first on a copy of the data. At the end of the day it may not be any cheaper (as your client should pay for the time to do this) but as you are using transactions batches there would be a full audit trial.
If you are interested in discussing this further please give me a call.