Let's see if I can get Danny limited to Bawb's room.
It's been awhile, but here is the skinny:
The newspaper thing used to have some merit before they switched to soy based inks, so save your time on that oldie.
What you have RW is essentially oxidation/pollution on the glass. You may also have some very light etching which only gives the pollution a place to anchor to, but I'm willing to bet most of your problem is just the oxidation/pollution.
Be very carefull with any acidic product like the one mentioned, it's known as CC550 in the trade, and it can be a game of russian roulette, 5 you win on, one you FOG like a whitewashed wall.
Do a quick test, get some #0000 steel wool from the hardware store, and rub a little silver dollar sized circle in the corner of a bad area, a drop of dish soap and a sponge is all you need to keep it wet while you cut through the skank with the 0000 grade wool. It won't take but 30 seconds, if you have success then you can skip all the chemical approaches that I would next recommend, and save some money.
Report back.