Hello, I need to let down the mainspring in a model 1857 and can't figure out how. A little help would be appreciated. Thanks. Gary.

Gary,
Under the dial you will see a click and click spring. Take the pressure off it with the key, move the click away from the ratchet wheel and let the key down easy.
Brian C.

Thank you Brian. I thought that this may be the method required, but decided to ask first. Regards, Gary.