I'm with blaster76. The aluminum can method is not that hard, avoid putting a potentially essential part at risk through over-thinning, and can be very convincing. In my first, somewhat ham-fisted attempt to use this technique, I made new muffler guards for a Tiger I. If you can get past the bad photography, here's a pic:
Not great, but acceptable. And a LOT better than I expect I would have done with the thinninh technique, which sounds quite challenging to me. The best part is, if you mess it up, just cut a new piece!