Boromir's Shield: Cover
I was able to find some vinyl that exactly matched the leather used for the film shield. I cut off a square piece and then, starting at the center, glued the cover to the outside of the shield.
The cover completely glued down. The vinyl was stretchy enough not to crease or wrinkle.
After the glue had time to set, I used an xacto knife and trimmed off the excess.
For the outside rim triangles, I contact-cemented styrene to the vinyl and then puttied the seam to make it blend into rim.
I re-painted the rim and added the brass rivets to each outside triangle. The boss was then epoxied to the center of the shield.
The final shield. I used a wash of black to weather the shield and sprayed a wash of brown to simulate splattered mud.