Do the third series Diana 58 “serial numbers” in the tap really make sense

[45flint]

My guess (but that's all it is!) is that these are "tracking" numbers within a production batch, to keep an individual gun's parts together during manufacture. The fact that they are out of sight, and on the most closely hand-fit parts of the gun (loading tap), may support that. The "58" on the cover plate may indicate another model (the 45 underlever perhaps) had a similar plate.

A similar practice is seen on late-production HW 55's. On early examples (serial stamped on the rear receiver section early in the assembly process), all or part of the serial appears in four other places. But on late ones (serial stamped on barrel late in assembly) an arbitrary 3-digit number - unrelated to the serial - appears in those same spots.

An interesting question though! I need to study my lesser-model old Dianas more carefully.

I am really torn between the two thoughts. “Tracking” numbers make sense to me and you do see this done in other rifles. But there is another side as well which causes me pause. There are numbers in the 200’s that are seen. 200 seems really high for a “tracking” number”? Would you really have 200 rifles in a batch to track, seems a bit crazy to me? Also the nail in the coffin of serial numbers would be a duplicate number, we haven’t seen one. I side weakly with serial numbers. Besides any theory which makes your rifle rarer and thus potentially more valuable should be supported.