…shows the address blacked out with a marker. However, a few simple adjustments to the contrast and some magnification reveal the address that the postcard was sent to…
Here you can clearly see…
Pollard State University c/o Pronghorn Java Pollard, AR 72456 USA
Here is the zip code 72456 on Google Maps.
@anabrams fan just pointed out the following: Just a few minutes away is Piggot, AR. Highpoints include the Hemingway-Pfeiffer Museum & Education Center. It includes a barn studio and the home of Hemingway and his second wife, Pauline Pfeiffer. Here is an interesting timeline.
The fact that the postcards were sent “C/O Pronghorn Java” means that Vanessa, who worked there, was the recipient and guardian of the postcards – which corresponds to the marginalia at the bottom of p231. And since we know that FXC received an unwelcome visit from someone after Eric (based on Arturo’s letter), then we can infer that Vanessa was not trustworthy. She likely disclosed the postcard information to Moody and/or Ilsa, along with the fact that Eric and Jen would meet there in the private room in the back.