I would be worried about that cheap metal bar fatuiging over time and giving way, it seems kinda thin for this application. Good thinking on the safety wire though.

I think there's room for improvement, possibly hardened hardware, but that would raise prices significantly. Does it flex when opening/closing the door? If so, it will fail soon.

Not to be taken offensively, just some constructive criticisms
~Nate

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95 Honda Shadow ACE 1100.
1999 Plymouth Neon Expresso. 2.4 swap, 10.5 to 1 comp, big cams. Autocross time attack vehicle!
2012 Escape, 'hunter" (5 sp 4cyl)