The use of clasps is postwar.2) all shells with the rim that has the seam in front have been produced during WW2, from April 1941 to November 1944, either fixed or swivel bails.
Since the production began, until 1943 the colour of the straps attached to the shell was the olive drab #3, from 1943, mostly on Schlueters, the shells started to be fitted with straps colour olive drab #7. Mid war helmets were fitted with blackend steel buckle with simplified design.This is true for Mc Cord Radiator manufactured shells, however all Schlueter shells have been produced during WW2.4) and last, also the color, the texturization and the shape of the shell indicate its age.Wartime shells are a little taller, in a darker shade of green.In postwar helmets sand is used to texturize the surface instead of cork.A distinctive characteristic of early war examples, due to the type of steel used, is that they were prone to generate stress cracks on the shell.However straps OD#3 can be found in rear seam late war examples too. Late war helmets have a blackened brass buckle with simplified design.Since September 1944 a new release hook, called T1 was adopted and seldomly mounted, though it became a standard only on years '50s production.and Firestone ceased the production before or at the end of the war.All other high pressure liner: Westinghouse, MSA and Capac were produced after 1950 too.To reach large numbers of potential customers they need to sell what they have produced. Advertisements are a form of marketing that promotes the product or service in a manner that reaches a large number of people.For example, an advertisement in the form of a store sign can be seen by anyone who passes by, which could mean hundreds or thousands of people per day.