Russell and Erwin Mfg Co Mortise Lockset

You very likely won't be able to find this spring anywhere. No manufacturer I know of provides the internal components of a mortise lock by itself. You will need an all new mortise.

We can help, but we need you to put it back together and show me a clear picture of the complete mechanism. That will allow us to determine if this is something we can supply.

If you don't want to do any of that, then your only other option is to try to fashion the spring yourself.

Thanks for these photos, they're a huge help! The mortise you're showing here is very similar in design to that which comes with our 42-009 lockset. The mortise is unfortunately not sold separately, though, so we can only supply you the complete lockset as you see it. For now, look over the dimensions below to verify that our product matches in size as well as design.

Alternate view of 42-009