That amp in the picture is build by someone I know. I think he used what he called «asphalt plates/sheets».If mounting on the steel bracket wall I would try and get some 1/4 inch thick rubber or cork (or thicker) to create some stand off distance.
A little bit of extra stand off distance is good for shielding.
Asphalt/rubber/cork is good to reduce vibrations but the standoff distance improves the effectiveness of the magnetic shielding.That amp in the picture is build by someone I know. I think he used what he called «asphalt plates/sheets».
I did not know that. Thank you!!Asphalt/rubber/cork is good to reduce vibrations but the standoff distance improves the effectiveness of the magnetic shielding.