I am not sure where from you bought this back. If from the Sinar dealer then he should have provided you these files, which are absolutely necessary. Other than that, you can contact Sinar directly: there effectively exists a library where all the ref files of the different back sold are stored, at Jenoptik (since it is a Jenoptik back). Sinar will certainly be able to get these files for you, but it is not a free service and costs about CHF 150,- to 200,-.
Best regards,
Thierry