Sound suppressors cut in half - photo

[baja]

I see a lot are K baffle style, and only one "washer" style.... does anyone know the name/efficiency of the 9th and 11th in from the left?
does anyone know how they were made? (looks like maybe piece fabricated and then sleeved over....)

I don`t have any idea about the suppressors but that sure looks like an M72 LAW behind the Maker`s Mark;