Help: Brunswick Ultona Reproducer Problem!

[ewok]

The Ultona reproducer on my Brunswick machine becomes loose now. There is a stop pin on the reproducer supposed to lock the reproducer in one of the positions to play specific type of records. I inspected carefully and the tip of the pin looks OK and the four small holes where the pin locked into also look good. The spring that push out the pin is also OK. However, the reproducer simply cannot be locked tightly!

Is the stop pin adjustable? If the problem is caused by the worn out stop pin, can I just replace it?

[ewok]

Here is the video to show what the problem is.
http://www.youtube.com/watch?v=AaP_h8Nnblw

[ewok]

I guess that I found the problem. The "lock pin spring" on the reproducer is broken, therefore the lock pin cannot fully lock the reproducer in its place. The picture shows where the lock pin spring is located.