I laced the cockpit coamings myself. Again, I used naugehide. I probably didn't use the conventional method, as it looks ok from the exterior, but the inside is not as refined. I may do these over using a different technique if I'm so inclined.
I had the upholstery shop sew in a welt bead around the circumference of the material and then cut and slit the material to make it conform around a section of water pipe foam insulation. Using a steam iron and puffing steam in it help to mold it around the foam. I used 3/16” bolt, nuts and washers to temporarily hold things in place I installed antique finished brass grommets and laced with 3/16” leather. I also made naugehide pads for the windshields and installed them.