Most of the slugs have a number 5 stamped on them
https://typewriterdatabase.com/1926-mercedes-4.19461.typewriter<br /> "Steile Sierschrift" (Steep ornamental font) <br /> RaRo foundry mark 5 circle I<br /> paired with<br /> RaRo foundry mark 57 AR

Most of the slugs have a number 5 stamped on them
https://typewriterdatabase.com/1926-mercedes-4.19461.typewriter<br /> "Steile Sierschrift" (Steep ornamental font) <br /> RaRo foundry mark 5 circle I<br /> paired with<br /> RaRo foundry mark 57 AR

the mark says AR for Albert Rodrian, one half of RaRo. If you ever see an R inside an octagon thats the mark for the other half, Alfred Ransmayer.
via Koponewt (aka Otto Koponen) https://www.reddit.com/r/typewriters/comments/1kg83kz/olympia_typeface/