McIntosh MA352 Mirror Finish Scratches

Since it's stainless steel, I'm wondering why you didn't just use windex, but anyhow, first world problem for sure. You could only make it better with an even finer abrasive polish than you already used. Maybe Simichrome?

I don't know, I'm definitely kicking myself. Thank you, I'll look into that. 

You'll probably need to find someone who specialises in metal polishing as polishing stainless steel to a mirror finish is a tricky technique to master involving lots of grades of abrasives and practice.

I don’t know if you will completely get them out, but I would try Flitz. Technique is everything. Apply with a soft foam or microfiber wax pads for cars and buff off with a microfiber towel. Straight lines only. This may minimize them to a point where you won’t notice if you’re not looking for them. Also, an acrylic car wax like Klasse might fill the micro scratches a bit making them harder to see. That’s probably the best you will do without going to a jeweler’s polishing wheel. 

I have the same amp but have only cleaned with the stainless cleaner my wife uses on kitchen appliances with good results. You may want to consider automotive metal polish (non abrasive). It works incredibly well without scratching. 

You need to find a professional that can do it and leave it alone. I was thinking to have it rechromed but it looks like the chrome goes under the heat sinks so it would be a nightmare to separate it. I use a fine soft haired paint brush to dust mine and if that doesn't do then windex with a microfiber cloth..... Of course I know that is a lot of help now.

This is not the main issue, but its annoying and disturbing that McIntosh hasni't helped.  I need to point out that I have contacted them about issues with my 352 and they have never responded.  I was in the market for Mac seperates and had questions that they never respnded to.  It may be why I decided NOT to get the $20,000 C53 and matching unit.  Not good that we spend this much money on audio equipment and they have no customer service.