To mark the centerline, set a compass to span something more than half the width of the leg. Draw an arc from corner of the leg. The point where the arcs intersect will be on the centerline. With a centerline point on each end of the leg, place a scribe on the point, slide a straightedge up to touch the scribe. Do the same on the other end. When you have the straightedge positioned so that you can touch both points with the scribe, and in each case it is touching the straightedge - without moving the straightedge - scribe the line. Use scribes, rather than pencils or pens, because they make more precise marks.
Grizzly is a company currently undergoing an upheaval. This brand was once known as a manufacturer of professional grade tools and equipment for woodworking products. Though, in recent years, that reputation has begun to slip a bit since being bought by the Chinese company SIEG. These days, whether the Grizzly product stands up to its previous standards of excellence often has more to do with what you are buying than the company itself.