It’s the door latch spring with flat ends. Good spare.
The spring on the right is correct

Who sells these ?

Is this the little spring on the inner lock mech?

If no vendors come up, I’d bet you could find something very similar at McMaster-Carr.

I assume length, diameter and wire diameter would get the “specs” really close to the original

We have made some custom springs of all sizes. There just needs to be enough demand to pay for the set up and hopefully sell a few.

These may be commercially available. If not we could look at these.
Mark

The main feature are the flat ends. They hook over posts in the door latch…..

True Value Hardware may surprise you with their collection.

Both are correct. There are two different lengths even though there is only one part number for the left or right doir latch. I have not been able to determine if it is anearly vs late issue. And the latches are different too as the mounting posts are different distances too.
The same spring is used on VW beetle door latches.
I doubt anyone makes them as there is no demand and it is a very special spring.
Why do you need one?

Right now I don’t need on, I just replaced the bad spring with a good spring I bought fro you years ago.
I was curious whether there is a source.