Wall plate (3) - Iron, Aluminium - Safety / Regulations

A trio of industrial signage and mechanical pieces from an old workshop and industrial center, dating from the early 1960s to the late 1970s. They are made of shiny, lightweight metal, and the large plaque of the Right of Retention (the law is still applicable today!!) has a wooden core around which the iron part was wrapped, therefore heavier and more stable.
Images accompanying the descriptive text.
They will be shipped with care, to avoid bending.