Shaggy toothbrush and a good oiling solved the problem. I'm fairly sure it wasn't actually rust, just oxidised oil.

Next problem - a "new in box" Cox .049s I bought recently is tight just like a new Norvel. I know this is normal for Norvels, but a Cox black widow????? Should I just do the 'oil it and turn over 100 times' thing like for a new Norvel, or do I have a problem here?

--Col