Bargman L-400 doorlock repair

[Derek in Calgary]

The back of the lock cylinder of the Bargman L-400 on my Trillium 4500 snapped off. I've replaced the cylinder but can't understand how the manual lever (black rubber tab protruding out of the rectangular hole in the inner faceplate) is supposed to function. It is on the end of the locking arm part # 10-40-090. There appears to be a spring tensioner on it that is broken. At present the arm just flops up and down. Looks simple but it has me scratching my head. Please note that I have the first version of the L-400. Also, the photo shows a coil spring that I attached for now to ensure the lock arm stays down unless raised by the key.
Any advice I could get about how this should function may help me to fix it and would be greatly appreciated.

[Lockman]

Here's a site to try. It has an exploded view of your L400 Bargman lock. It might help. Also, you can search for Bargman L 400 lock views for additional pix's.

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