I have a Zenith Mod.6G601M portable that's in excellent
shape except that the case is really dirty. It has
the brown and tan "suitcase" cloth covering and it was
loaded with dust when found. I am a little leery of
using a lot of water or solvents on it. Is there
something I can use to remove the dinginess without
hurting the sizing or what ever finish is in the
cloth?

I have a Zenith Trasoceanic 8G005YT and It's 6G001Y companion that have a black leatherette covering. They were filthy from decades of storage in a garage. I used Windex Glass and Surface cleaner with a small soft scrub brush and they cleaned up beautifully without hurting the material. The bottle is clear plastic and has a purple background color on the lable and the cleaner liquid is clear and NOT blue. You should be able to find it in any grocery store. I finished it with some Armor All conditioner and they look like new now. If your radio is leatherette covered it should work wonders. If it is real leather, I would be cautious. Hope that helps.

John