Glued two 3/4” finished plywood panels for top mantle covered edges with 1 1/2” half round to make a more robust FP mantle. Painted with high temp rust oleum.
Forgot to mention, glued top down with Titebond III for slow cure & 2 sided sticky tape to hold in place with added weights. Got 1 1/2 half rounds at White River on-line in Arkansas. Well packaged & Fast delivery.