Totally agreed, Raf, and on Leonardo da Vinci's drawings as well.
They should in any case be taken
cum grano salis.
What makes me think that wheellock mechanism from the combination gun in Venice that you reposted could be somewhat later than my tinderlock is the fact that the internal trigger release spring already employs a screw, instead of the plain rivet there is on my lock.
Here's another early snapping tinderlock from my collection with a highly interesting mechanism, ca. 1520's-30's. It is remarkable for having an internal tumbler and a double-arm serpentine main spring. It's all riveted and bolted, no screws.
Best,
Michael