Unfortunately for the CJ-3A, during it's production run, Willys was more focused on selling their Wagons, Trucks, and Jeepsters.  So the 3A saw very little advertising exposure in the mainstream media.  Most 3A ads were published in farming magazines and journals.

This is an ad from a 1950 issue of Country Gentlemen:

Above is a dealer brochure from Cleveland, OH demonstrating the "versatility" of the CJ-3A

Here is another ad from Country Gentleman for the Monroe Hydraulic Lift


Once again, another ad from Country Gentleman

Here are a couple close-up shots of the photos in the above ads:

Probably the earliest CJ-3A ad.  Published in Time magazine, November 1949:


1950 Time Ad

Here is a collection of 3A ads from Belgium

Cuban Lottery Ticket



Here are a few ads submitted by Robert Firth: