Hi Steve,
I think your movement should have a small click access hole on the edge where the mainspring barrel is located (see images). The images below are of a different Elgin movement but should be similar. Give the let down key a little clockwise turn and then gently push a pin into the hole to move the click back and then let the key spin slowly.
Hope this helps Steve,
Bob
![elgin_mainspring_1.jpg](./download/file.php?id=211&sid=40af3608d1cc692baa06e90473650062)
- Elgin mainspring let down
- elgin_mainspring_1.jpg (74.47 KiB) Viewed 2686 times
![elgin_mainspring_2.jpg](./download/file.php?id=212&sid=40af3608d1cc692baa06e90473650062)
- Elgin mainspring let down 2
- elgin_mainspring_2.jpg (77.01 KiB) Viewed 2686 times
Enjoy!