I would question why only those assemblies with under 50 Hours being inspected. As a good engineering practice I would suggest inspecting every one of the things. At least they are calling for grounding the aircraft as it must be a critical problem should thing fail.
Also...a second question is it would seem Bell might not know which parts actually had those particular kinds of questionable bits installed except to a certain time period they were in the system during build of the parts. If that is so....then that is a bit troubling to me.