ALL single page views are processed by single.php, which in turn uses templates/content-single.php. That is hard wired.
So, to use a custom single page view of a cpt, you’d have to use a replacement templates/content-single.php that has a check for post type, and uses the alternate display code. That would be easiest, I think.
Or you could change the code at the single.php level and use your content-gasket.php instead of content-single.php. Either approach would work, I think.