That's an impressively complex mechanism for such an old lock.

I'd suggest it was used on a trunk, as it looks like the plate is secured by claw or hook arrangement. It could have beena sliding gate, but that would be unusual back then, plus the key only enters from one side.

The key would look like the negative of the ward plates at 8 and 10 o'clock, plus have a deep cut at two positions to avoid the two long radial wards.

For all the complexity of the mechanism, a bit of curved wire through the keyhole would likely press the detecting lever, & opened the lock.

Thanks for sharing the photos.