Driver Side door stuck? Help!

Hey guys,
The driver side door on my 64 Cuda is stuck. I've pulled the door panel off,
and and can see the linkage inside. The rod from the inner and outer door handles moves its full travel, and the lock will slide up all the way (unlocked position), but only partly down (locked position).
However, the door will not budge.

I'm not real clear on the mechanism, does anybody have any tips or ideas on getting this door open?

A scan from the shop manual maybe showing the mechanism?

Any help is appreciated!

Thanks!
Author: admin