Restore Date On Standing Liberty Quarter?

Here is the recipe as I found it on several metalsmithing/jewelry sites(I have not personally tried it, yet...)-

10ml NH4OH
10ml H2O2
40ml CH3OH

Maybe I'm a little too mercenary in my thinking, but the only SLQs (other than 1927-S) that might have any value IF you were to successfully restore the date are those prior to 1925. I know that the type 1's from 1916 and 1917 have a different reverse from the type 2s, but is there anything that would, as an example, distinguish a dateless 1919 coin from a dateless 1926?

I don't have enough knowledge on the SLQs to determine a dateless 25-30 versus pre-25 (the important ones). The vasty majority of the dateless SLQs, however, will most likely be pre-25 because of the poor design.

I tried out the ammonium hydroxide-peroxide method. The ammonium hydroxide-peroxide method didn't do anything but cause discoloration like the ferric nitrate method, so that doesn't work. It, too could be removed by a pencil eraser. RATS! Actually glad though, because ammonium hydroxide is very bad smelling- wouldn't want to be using that stuff routinely to restore dates to silver.

I also have a few dateless Walking halves, in addition to my 40+ dateless SLQs. I hope someday we can come up with a way to restore the dates on these. Could turn worthless buillion into something worth a little more than buillion.

I looked back in the archives and found that someone had a product named "Silver Date-Back"

Yes, I agree. These chemicals are very potent and should be handled with caution. Ammonium hydroxide is a very awful smelling chemical. Nitric acid can burn the wood on a table so you should lay some newspapers of clothes down if you work with any of these chemicals. And wear rubber gloves.

I'm just disappointed to find out, after all these years, that I shouldn't be ingesting methyl-alcohol. It goes so well with a cherry and a little ginger ale. I guess I'll switch to paint thinner.

I didn't know ammonium hydroxide is a precursor for crystal meth. I thought Ammonium nitrate was and this is why when I go to get fertilizer for my garden, they take down my name and number (ammonium nitrate= main ingredient of fertilizer). Or can both be used?

NH4NO3 is one of two ingredients in ANFO, of the most common mining explosives. ANFO is also what brought down the Murrah Federal Bldg in OK City and Khobar Towers in Saudi Arabia- that is why they want your pertinent info when you buy fertilizer.
http://www.globalsecurity.org/milit...ves-anfo.htm

Morgannoob is correct, NH3OH is anhydrous dissolved in water. Anhydrous is used in the drug manufacturing process because anhydrous is much more common and readily available due to farming but anhydrous is much more dangerous to handle

With all of that said, unless you have specific training in the handling of hazardous materials and have sturdy PPE available, then you should not play around with these chemicals. If one wants to learn more about processes to etch silver, then I would suggest perusing forums dealing with metalsmithing and jewelry making- those types of people etch different metals all the time and that has been the source of most of my info as well.