I recently found my friend a Centenary 2500 with a Cal. 333. from Italy on the bay and it looked interesting to say the least! The dial had an almost bronze effect, which I'm guessing is to do with sunlight or possibly even smoke damage..nicotine stains possibly seeped in? I actually quite liked it.. Well. He received it today and being the chancer that he is, tried to clean the dial....the results impressed me.... Before: View attachment 15649 View attachment 15650 Midway through: Many buds later: Can't believe that that it's the above - It looks like a different watch!! End result: Needless to say. He took a chance buying it, but the end result speaks volumes..it took him a few hours but it doesn't appear like he wasted his time!
Looks ok - why did he not remove the hands though? what did he think he removed - nicotine or the varnish?
I'm not sure but I shall ask him. I think he took a huge gamble and I wouldn't even dare touch my dials like that! But I think it looks like the staining wasn't entirely age related as it doesn't look naturally aged from the first pic.
I've had luck with gently rolling rodico on the surface of dials to remove grime. I've heard of people using standard jewelry cleaner liquid, but I am too weary to use any chemicals after severely wiping away the text on a Hamilton dial with dish soap in my early days...
very impressive and hard to do.....also very fortunate that the printing was nicely preserved...I would not have attempted this!!
Different top coats were used by different companies during different eras. Be aware that you might choose the wrong solvent, which would remove the top coat and subsequently destroys the dial instead of just cleaning it.