La fine dell’Eldorado

On the backcover there is advertisement for new Kit Willer series which was never published:

Intelligent and fearless... cunning and contemptuous of any risk...
a skilled horseman and good marksman...
this is what little Kit Willer, the son of the Indomitable Tex, has become over the years. Raised in the rough school of Navajo warriors, under the guidance of Tiger Jack and Tex Willer, Kit is now seasoned enough to face his first adventures, and when the desperate message from Kit Carson arrives in the Navajo reservation village where Kit lives with his father, the time leaves a red trail on the page of Kit Willer's destiny!

Friends of Tex!
Read, from the very first issue of the new series that will come out in a few weeks, the fascinating adventures of Kit Willer. You'll be thrilled!..
Kit, Tex, and Carson, a formidable trio launched at a breathtaking pace into the most exciting adventures!

More info on the series can be found on this page.