Turn off "Restart" course

Howdo. This isnt out of the box (that I know of) so am hoping someone out there can save the day. To summarise:

• I have built several modules, with a standard end of course assessment, for a client over the last year with "On restart: prompt to resume" on.
• Said client wants a pre course assessment added in, so if they pass this, the course sets to complete and they dont need to go through the learning (I changed it to "On restart: Always resume" here).
• When replacing the original SCORM file on the Totara LMS it all goes a bit wrong and the course doesnt load. Turning it back to "prompt to resume" fixed that.
• But now if they fail the course, close it and click "Restart" they can retake the pre assessment.

Basically, I need to keep the setting "prompt to resume" on, but somehow turn off the "Restart" bit of the popup, highlighted in the attached pic. Any genius life savers out there? 

Thanks,

Mark.