[fernando]

Excelent,Berkley.
The clearest way to show it.
Eventualy the examples i have within this area, would not be good for such demonstration.
One has a similar shape and decoration, although of poorer quality, without any maker or proof marks, but with a fix barrel.
The other is a Liege marked one, with a screwing facility that is stuck and, despite all reasonal efforts, i could never unscrew it. I think this happens often with this system or, at least, i have already came across with a few cases in the Net.