it's working!
Polyurethane glue is super strong.
When gluing the pieces it's a good idea to put a drop of glue on a surface near the pieces: this way you can see how it cures and expanses, and you can wait for it to be truly hard before trying the part.(takes more than 24 hours)
Apparently barrel coaxiality in not such a big problem as long as the left side of the lock is decently positionned.
Now you guys can fix all those old Tanaka Revolvers sleeping in their crates waiting for replacement parts that will never come!