Ok. I'm not knowledgable enough to be of much help, but I will at least give some ideas and help put the thread back into rotation.
Check the fuse for the solenoid, actuation of the solenoid if it has power, and verify the linkage works. If all of that checked out, I wouldn't know where to go from there. A member here named Jerry Bransford seems to know quite a bit about these transmissions in particular and may be of benefit here. You might consider shooting him a PM and see if he's got some insight.