I spent the some time after work working on the cowling since my order from Spruce came in last night. I received my piano hinge for joining the two cowling halves. I chose to spend the extra money on the extruded piano hinge which is a fair bit stronger then the rolled piano hinge. I marked out 1 inch on either side of the joint. and then marked out the rivet line. I plane on using countersunk 1/8″ rivets to attach the piano hinge. I marked both sides out and used 1 inch spacing for the rivets. I drilled out the top side using packing tape to hold both halves together. Below are some photos.
Annular Cowling Piano Hinges