Let's See Your Magicians Coins

Someone recently showed a hollowed out Magicians coin and it brought to mind a coin I have so I thought I'd share it here.
Here's a coin I bought simply because it looks like silver and it was only $1.00.
When I removed it from it's 2X2 and inspected it closer I came across..... pictures are better then words the photo's explain it all.
The coin is the proper size but you guessed it it's under weight at 1.8 grams and is not magnetic. It also does not separate.
I belonged to the International Brotherhood of Magicians and practiced magic many years ago and I never came across a item such as this.
I've seen many coins hollowed out and different coins hidden inside used to perform various tricks but never anything as small as this.
I can also see where this Coin could be used for a floating coin trick but it must have been for closeup table magic
This Looks to me like a very intricate machining job.
It was suggested on one of the US sites that this is quite easily done with the use of acid, however I simply can't see how it could be accomplished using acid.
Couple questions now are the 1968 US ten cent coins supposed to be magnetic or not and can anyone tell if this is a real ten cent coin that was used?

Cheers, Bill