How would I go about "resetting" access to a course that is marked completed in the SCORM tables?
Through the ScormEngineManager (the API), you can use DeleteRegistration, that would be an option. Also, if you have any instancing concept (which we could tell by looking at your integration...) then you can create a new instance of the registration... that would be a fresh start. Either way would work for you.
As always, if you have questions, send us an email at firstname.lastname@example.org