How do you clean a McIntosh amp?

I have just purchased a McIntosh 240 amp. It is quite dirty. I don't believe the chrome is pitted, but I'm afraid I will lose the lettering on the chrome as I clean. Any suggestion on how to clean the chrome? Is WD-40 okay?

I thought I would clean the tubes with a dry, cotton rag being careful not to touch the tubes with my fingers.

Any suggestions will be appreciated.