K1520_A:A6M5 Type 0 Model 52, the most effective variant, developed to shorten the wings to increase speed and dispense with the folding wing mechanism.
K1520_A1: same as K1520_A but added weathering washes and panel lines

About the scale:
From the photos of K1520_A, the model's wingspan is about 8.3cm (3.27 in), and length about 6.4cm (2.52in) . The full-scale A6M Zero fighter had a wingspan of approximately 12 meters (472in ) and length 9.06 meters (357 in).  

Using the formula:
Scale = Wingspan of the full-scale plane / Wingspan of the model plane =1200/8.3≈144
​Scale = Length of the full-scale plane / Length of the model plane =906/6.4≈142

Therefore, we can estimate the scale to be approximately 1:144. However, keep in mind that different versions or manufacturers may use slightly different dimensions, so it's not advisable to rely on models from different manufacturers as a determining factor. The calculation and resulting scale are for reference purposes only.

The Mitsubishi A6M "Zero" is a long-range carrier-based fighter aircraft formerly manufactured by Mitsubishi Aircraft Company, a part of Mitsubishi Heavy Industries. It was operated by the Imperial Japanese Navy (IJN) from 1940 to 1945. The A6M was designated as the Mitsubishi Navy Type 0 carrier fighter, or the Mitsubishi A6M Rei-sen. The A6M was usually referred to by its pilots as the Reisen (Zero fighter), "0" being the last digit of the imperial year 2600 (1940) when it entered service with the Imperial Navy. The official Allied reporting name was "Zeke", although the name "Zero" was used colloquially as well.

The Zero is considered to have been the most capable carrier-based fighter in the world when it was introduced early in World War II, combining excellent manoeuvrability and very long range. The Imperial Japanese Navy Air Service also frequently used it as a land-based fighter.

In early combat operations, the Zero gained a reputation as a dogfighter, achieving an outstanding kill ratio of 12 to 1, but by mid-1942 a combination of new tactics and the introduction of better equipment enabled Allied pilots to engage the Zero on generally equal terms. By 1943, the Zero was less effective against newer Allied fighters. The Zero lacked hydraulic boosting for its ailerons and rudder, rendering it difficult to maneuverer at high speeds. Lack of self-sealing fuel tanks also made it more vulnerable than its contemporaries. By 1944, with Allied fighters approaching the A6M's levels of manoeuvrability and consistently exceeding its firepower, armor, and speed, the A6M had largely become outdated as a fighter aircraft. However, as design delays and production difficulties hampered the introduction of newer Japanese aircraft models, the Zero continued to serve in a front-line role until the end of the war in the Pacific. During the final phases, it was also adapted for use in kamikaze operations. Japan produced more Zeros than any other model of combat aircraft during the war.