How does one deal with a minor grunge mark on a coin like this one. I brought this with the intention of giving it away, but now as I was photographing it, I see this anoying mark, amost like tape glue.
Acetone. Swish it around for a couple minute in acetone, do the same in a fresh bath of acetone, possibly a third bath, and then a flowing rinse by pouring acetone over it while holding it. the hold and let air dry. This will probably take less than a minute. It should now be clean and you will most likely clearly see the damage done to the proof surface by your attempt with water and a soft tissue. When I am dealing with a proof I never let anything solid touch the surfaces, they are delicate.
Am guessing by soft tissue, you are referring to something such as kleenex, or toilet paper. Being composed of wood pulp, these products will leave hairlines on the coin. A pure acetone (this doesn't have the additives that acetone used in nail care has) soak, with a rinse in distilled water, then letting the coin air dry is recommended. Also, when air drying, place the coin upright on its rim.
wow alot going on on that coin words, yeh he he he words, lol (beavis and butthead) will this get censored??
I'm a big fan of that coin, when turned right, the lettering (dutch architect names) on the one side going around in a circle is supposed to look more like this, a portrait of Queen Beatrix, and dutch architecture book spines, made to look like building rising up on the reverse in a circular pattern. Yes, it's a busy design, but it's busy with a purpose. I'm a big fan of that one!