@buherator I'm basically at elementary schoolkid reading level, and this is written in classical Chinese which means that facing this I'm basically illiterate, but the name 南懷仁 is present in the inscription, which is the Chinese name for this guy: https://en.m.wikipedia.org/wiki/Ferdinand_Verbiest
@buherator I think it's this: http://www.battle-of-qurman.com.cn/literature/Stary-Verbiest-1994.pdf Check out page 219 for a picture which looks very similar to your inscription, and page 220 for the statement that one of these cannons is in Budapest (:
I think the script on the very farthest left side of your image isn't Chinese, but rather the Manchu script. If so, that would confirm that these are indeed the described cannons.
@buherator Wish I could find a better image that isn't a grainy book scan, though 😆
@buherator Nice!!! These are beautifully cast, and it's super interesting how they ended up all over the world :D