The two instalments of the Japanese Starlog magazines that contain material relating to Star Fleet have become quite famous, thanks to photos and scans shared on twitter and elsewhere.

November 1980

The November 1980 instalment contains a 4-page poster displaying almost everything from the show: hero and villain characters; X-Bomber, Dai-X and the Alliance battlecruiser; as well as pictures of the battlecruiser's bridge (interestingly featuring the Imperial Master) and the X-Bomber bridge.

The reverse of this poster shows a series of black-and-white images from the 1976 Wonder Woman TV series.

The only other reference to Star Fleet in the magazine appears on page 24, on a double-page spread showing then-currently-airing shows in Japan.
There is a small, black-and-white image showing Shiro, Lee and Hercules inside the EDF command centre, which is something that never occurs in the show.
This photograph is used on the cover on one of the Portuguese notebooks, but this reproduction of the image is much wider and shows General Kyle and the two other main members of the EDF command staff.
From the fact that Shiro is shaking the hand of the "number two" officer, this looks to take place after the events of the show, once the Alliance planetoid is destroyed.
Either this photograph is meant to have occurred some time after the events of the show, or the command centre has weathered the effects of the Alliance missile barrage relatively unscathed.

December 1980

The December 1980 instalment contains a white-on-black line art cutaway illustration of Dai-X, along with illustrations of the three Dai-X fighters, and detail images showing the Dai-X junction sequence, as well as detail images of Braincom's cockpit and Dai-X's chest missile launchers, wrist-mounted guns and the foot-mounted laser.

I'm not certain what features on the reverse of this poster.