How did they make this pugio scabbard?

[Magnus]

After reading Cesar's tutorial on how he did the etching and silver solder inlay, I was wondering how the Romans built this type B scabbard. It looks to me that the brass areas were likely protected by some kind of wax, while the rest of the plate immersed in a chemical etchant or darkener. Here is the picture from Raeticus's site, at www.romancoins.info/ :

[url:32otbg27]http://www.romancoins.info/IMAG0080.JPG[/url]

Am I right in this presumption on how they got the plate detail? I looked at it, and I can't see anything that would tell me the brass area was a type of inlay.

Also, does anyone have a picture of the bottom of this scabbard?