The stamped diameter of the tube looks to be 21.0mm?? The inspector's marks are crowned instead of spangled. Interesting mark beside the encircled >>ELG<< but I cannot make it out for now. Tubeset knitter had the initials of >>NM<<. There is quite a bit of wear on most of the marks including the top rib, which I have no idea for now.

Serbus,

Raimey
rse