I was just gifted my great grandmother's Presto Cooker Canner no. 21. I know almost nothing about canning but can't wait to get started! It looks like it is missing a piece (
Amazon.com: Presto 01781 23-Quart Pressure Canner and Cooker: Home & Kitchen
Presto 16 Qt. Presto Cooker and Canner - Woydziak Hardware