Here is a cool promotional item for In Through the Out Door from Japan. This Letter Pad is housed in the same designed brown paper bag as the outer paper bag for the LP cover. The paper bag and the Letter Pad has printing on the bottom with the Swan logo and its mailing address. On the back of the letter pad, it says, “Warner-Pioneer Corporation Led Zeppelin Original Letter Pad Not For Sale.”
Most likely this piece was complimentary for customers who purchased the In Through the Out Door release.