If you can get the crud off and just get back to tarnished silver, stop there. Keep as much patina as you can, since it took many years to develop.I think you're right. I did a vinegar bath which cleared away most of the crusty stuff. It's now looking more like tarnished silver. I was able to make out the serial # on the barrel now too. 138727. If the date charts are correct, does that put this as the first year of production for the single ring? The $9.95 price tag on this is definitely worth it if just for conversation value.