vintage Dr Sholl's advertising, 1930/1940s letter press printing block

Old letter press vintage printing block for a Dr Sholl's newspaper advertisement or advertising flayer. It measures about 4" wide and 3 3/4" high. The raised metal lettering (lead, tin or a lead-tin alloy) is fastened to a wooden block.

We're not sure of the exact vintage of this block, but we're guessing 1920s or 1930s.

The fourth photo is a mirrored copy of the lettering. On the actual printing block, the printing is reversed.