Rusty Key

Rusty Key
Information
Source	Gunther (60 Museum donations)
Sell Price	Cannot be sold

The Rusty Key is obtained from Gunther after donating 60 items to the Museum. Its existence is first referenced by Jas and Vincent in a cutscene.

The item can be found in your Wallet in the The Player's Menu on the Skills tab.

It is used to enter The Sewers.