I've never seen one of these outside the pages of books either.
An incredibly beautiful helmet, congratulations!
It's a model 1886 helmet, and was worn like this up until 1898, I believe.
Yes, it's all silver fittings configured.
There's another example shown on page 73 of "Deutsche Offiziershelme 1870-1918" Band I, which is in the Bavarian Army Museum in Ingolstadt.
If anyone does not have this 2-volume book set in their library, I highly recommend them.
Best Regards,
Alan