Hi Lee,
Sorry for delayed response. I suggest that you try this in a test environment and see how it behaves. I would suggest to create a test environment and use HDB that you have from old Hansa instance and import it into the test environment as well as copy all the attachments.
If you encounter any problems please let me know and I will do my best to help you resolve them.
Best Regards,
David D.
HansaWorld