Hello - I finally found my dream amp at a price I could afford...a good old SWR Super Redhead. As I unpack this for the first time and play it, what are things I should watch for? Obviously, things like "does it make any strange sounds?", etc. are something that I hope to notice right away... Should I pull any covers and look at wiring? Look for cracks/breaks in cones? Just play it until something appears wrong? Tubes? - what to look for? This is a pretty common amp or at least brand, so hopefully there is some advice out there. Obviously when you buy a used car, it's smart to have a trusted mechanic go through it first. I rolled the dice and have to trust the word of the person I purchased it from. Tech and electronic guys - what should I look for?