Any Belloti cymbals I have handled have all been very heavy, which meets the standards of the days, in which they were being made. The older Ajahas were usually in this vein too but had much different hammering . I used to think that the older Ajahas were not Italian but I now lean towards, the belief, that the maker's were always Italian but that over the run of the brands existence , the production of them was moved around between several makers, eventually becoming a rotocast product , out of uFip.
I haven't ever had or handled a Zanchi , that resembled a Belloti. Zanchi arrived on the scene , as a distinct brand, sometime in the late 40's it seems, and by then much lighter cymbals were in demand. I currently own some Zanchis, that date from the 50's for sure and they are pretty unique. While they have characteristics that would indicate their Italianness , the tooling and hammering are sufficiently different to set them apart but then they morphed over the years too.
The small K Constantinople, has likely been cut down from a 14" or maybe larger cymbal, that was hopelessly cracked. Check it's diameter , 8 ways. A good job , of course would yield a pretty round cymbal but a less good job , would yield an oval or lobed one.