To me, it seems that this coin might be coated with something. Some areas on the edge and seem to show copper and there's the detail noted on the previous post. Weight of the coin may be a little tough because with a +/-5% tolerance allowed on the weight by the mint, the weight of the copper may be within that tolerance and so it would be difficult to definitively say that the copper has been removed.
+/- 5% = allowable mfg tolerance(might be 10%, can't remember)
Total zinc/copper ratio = .975/.025 * 100% = 2.5% but 0.8% of that is planchet alloy so pure Cu plating percentage of total is 1.7%
So, one could remove the 1.7% copper plating and still be well within the allowable 5% tolerance of manufacture.
Dont let that stop you from buying a scale though.
Great tool for detecting off metal fakes.