Will alumium work for a firewall? I have an old "Do Not Enter" sign and think I would look cool to see it when setting inside the cab or turn the other way on the outside.
It should work. They are pretty thick. The one I liked best was made from a stop sign from the 40's. The letters were pressed into the steel. Even though it was painted you could easily see the lettering. PS. "Prince Albert in the can" tins make great patches for holes in the plywood floor boards and old license plates for m/cyl access doors.