I found the alignment pin was dragging on the receiver (the receiver is a crude prototype, and needs to be re-done). I removed the alignment pin, and added a small, spring-loaded pin on the arm, to help push it away from the head. It's now working nice and smooth, with very positive location at both ends of the travel.
Well.... Back to trying to "will" the pneumatic parts to show up, so I can finish this bad boy.... I cannot wait to see it working on its own.
Regards,
Ray L.