I'd rule out the Check Airman. In the US, that is normally term for a company pilot who does company checkrides. You've basically got FAA Inspectors (who are government employees) and Designated Examiners (who aren't) but who are granted the authority to issue ratings. So while an Air Carrier Designee will be a Check Airman, a Check Airman doesn't have to be a Designee. I've held Check Airman letters but I'm not a Designee.
Most 142 centers will have a Designee/TRE on staff or who they work with. I've sat in on one 142 type rating oral as an instructor watching a Fed watch the Designee. That was a fun room.