Is that picture of his vehicle from in person, or his website? Looks like the two billboards on the side are photo-shopped on, and rather poorly at that. I wouldn't be surprised if his truck is plain white. His tools inside are in jeopardy daily with that on the side. I stand to be corrected.
Edit. I snooped his pictures online. Looks like the billboards on the side are removable, so maybe only used when at gun shows etc? Good on him for trying, seems legit.
My friend checked with the Ontario Chief Provincial Firearms office and confirmed that Gun-Medic holds a valid Business Firearms Licence for gunsmithing.