Don't use an acid test on anything like this. Most decent jewellers or pawnbrokers will have a laser gun which can verify the type of metal.
Laser gun... they are fancy!
I had a stonker in the 1950,s.....wish i had it now,it was made of cast alloy, and lit up when i pulled the trigger, and it made a crunchy whirring sound....just like a real laser from....the 50,s.....i even had the box it came in....and it had my hero,s pic on it......Dan Dare..Pilot of the Future....