Update: Irene, camera specialist from Camera Fix, replied to my email:
"
We can assure you that our technician followed the appropriate procedure to repair your release mechanism. We also find it very common that when customers who have vintage film cameras leave their cameras sitting idle for months on end, problems can occur and stiffness can re-emerge.
"
The problem was with the focus mechanism rather than the shutter release. The camera was idle for about three or four months.
I am not sure how to interpret this reply but they do not appear very enthusiastic to inspect the camera and offer warranty repairs. I am wondering if I should get the camera inspected by a trustworthy repairer and forward them the report. Or just give up on Camera Fix altogether and repair my Super Ikonta myself following Chris Sherlock's video.
It also looks like I an not the first customer experiencing this "very common" issue.
The posts in this thread suggesting that the best camera service in Australia is B&H are not very encouraging either.