I don't see a cameo effect, sorry. Also have never heard of a 1961 silver nickel. Unless you're using the term "silver" in just referring to the excellent reflectivity of the coin. I think it's a nice coin, thanks for sharing!
Sorry i just assumed because it said a 1961 silver proof set but it's from the u.s. mint. That confuses the crap outta me.
That's because the proof sets were silver sets, but only the dime, quarter, and half dollar were silver up to and including 1964. After that only the half dollar was silver and it was reduced to 40% and was silver clad. Many sellers on eBay and even craigslist.com list the 1964 and earlier proof sets as Silver Proof Sets, which is really a give because 3 of the 5 coins were 90% silver.