I don't know how well the G would work out with metal,because when I did it while chopping it,I had to flip and mirror it. That means the stamp wouldn't show up,and it would bulge instead of being stamped in.
ive got a beat up tailgate that the m and the a is still good. if i can get my hands on a good one or atleast the word mazda cut out and sent to me, ill most deffinately do it. as for the g, i think you can take the a and cut the top off and mate it to the bottom. there will be alot of bondo involved....lol