Did you know that PS: The Preventive Maintenance Magazine
's Reader Service pre-dates the magazine itself?
Yep. It goes back to Army Motors
, PS's predecessor, where our creator, Will Eisner, worked before he established PS. As you can see from the image below, it was called, Sgt. "Half-Mast" McCanick's Question Dept. Perhaps it should have been called the Answer Dept., but either way, it was all about responding to Soldiers' questions so they'd have the latest and best information at their disposal.
Here's an example question and answer from the July 1942 issue of Army Motors
(click on the image to view the entire issue at the RadioNerds website):