Parking Brake Lever Washer

[Trap62]

I'm in the process of rebuilding my rear drum brakes and I found out that I'm missing a washer that goes in between E-Brake lever and the rear brake pad. I've seen it referred to as either a "Wavy" or "Spring" washer (see picture for reference) and I can not find a source on-line to purchase one. I want to get the right part since the brake system is kind of important -- any suggestions would be appreciated. Thanks!