Seized Bargman L-54 / L-55, help?

[bredlo]

Bought this lock on eBay last week, and when it showed up it had quite a bit of rust. Nothing would move.

Gave it a bath in white vinegar, which removed the rust beautifully. Used a spray lubricant, but it still won't move. It may be stuck in the locked position, I'm not sure ~ either way, I'm wondering if the spring could possibly be causing my troubles? Seems like one of the few moving parts.

Thoughts? Suggestions?

Video here:

https://www.youtube.com/watch?v=5LSPcxAqjeU