Welcome to the forum, Andi
.
I hope the members come around and give you some comments on these cannons; not Matchlock, as he will be absent for a while.
My own knowledge is extremely limited but i will dare say that the cannons on the left and right are earlier than you are guessing; but don't take this too seriously
As for the one in the center, the breech loader, i would risk the opinion that it misses part of the barrel, judging by its proportional dimensions.
Let's hope other members chime in to correct my shots and offer a better judgement.