Broken Dulciana Session Mantle Clock

I have always loved antiques and I found a Dulciana mantle clock at the local thrift store. It was made by the Sessions Clock Company and is an Eight Day, Turn Back, as indicated in the label. The pendulum, the keys and the glass are missing. I know you can purchase these parts in the internet but I don't know the exact specifications (for example, the key size or type). If you can help me it will be greatly appreciated