Japanese Tazawa Shogen Design - How To Tell Them Apart?

I have the 3 Sen of the above set, with the zig-zag WM (Scott 141).
How do you visually distinguish between Flate Plate and Rotary printing?
I see that the Flat-plate prints got 3 Michal cat numbers: 114IIIE, 114IIIA and 114IIIDl - what is the difference?

And a general question: Sometimes different perforations get different Cat numbers. Here, they are not. What are the rules about that? For example, Michel 114IIIA, Stanley Gibbons 233, Sakura 169, all refer to the same stamp with different perforations.

Either my question is too hard or too boring.

Hi Rob - we cannot see any pictures of the stamps. That is probably why no response :)

Thanks Nora.

My own stamp is pretty much beaten up, and so is my scanner, so here is a typical image.

As for Flate Plate print vs. Rotary print, and different perforations under the same catalog number - these are general questions, and I don't have representative stamps.

Rob,
The flat plate vs rotary is a USA hot topic,
It might apply here,
One big thing mentioned there is forget about the measurements
There's easier ways to narrow it down
I could be wrong, might be worth it to look into, maybe

How do you tell them apart in USA stamps?

Rob,
https://stampsmarter.org/learning/M...methods.html
Don

ROTARY die is smaller than FLAT plate

Correction ------Rotary stamps are longer in either direction .

Following information is from Sakura (1999) catalogue:

Flat plate, old die: 19,0x22,5mm; used until 1925, paper both unwatermarked (white paper) and zig-zag watermarked (granite paper)
Rotary plate, new die: 18,5x22,5mm; used in 1926-1935 (zig-zag watermark on granite paper), 1937-1938 (line and semicircle watermarked on white paper)
Flat plate, new die: 18,5x22,0mm; used in 1926-31 (zig-zag watermark on granite paper), 1937 (line and semicircle watermarked on white paper)