The U.S. Mint struck two different 1936 Proof Buffalo Nickels. The first finish is referred to as a Satin Finish and the second is referred to as a Brilliant Finish.
The 1936 Satin Finish Proof Nickel was the first variety produced from the two. It is believed that the Mint might have changed the Satin Finish to a Brilliant Finish since the Satin coins resembled circulation strike coins.
The Satin Finish and the Brilliant Finish seem to have about the same survivability in all grades combined. In high grades of PR67 or higher the 1936 Brilliant Finish Proof Nickel is significantly scarcer than the 1936 Satin Finish.