Not much is known of the original boots. They might possibly have been brought to Spain by Clint Eastwood who originally sourced his wardrobe from local shops in America and from pieces of wardrobe he'd used originally on the series Rawhide.
The original boots are made out of rough out leather and are tan in color. Blondie's boots are unique in that they are extremely plain with no decorations like those found on most other cowboy boots. They do not even have pull straps on the sides.
They are narrow "square toe" style boots. and have a flat top called a "Stovepipe" top (scallops).
Eastwood normally wore his pants over top of the boot but in some scenes he wore his pants tucked into the boots revealing that they are mid calf in height.
Carlo Simi was the costume designer, but Clint’s look is not attributed to anyone in particular. Eastwood reported that he had bought his costume from a Santa Monica wardrobe store, borrowed the leather gun belt, pistol and suede boots from Rawhide, the tv series he played in the 1960s, before starring in A Fistful of Dollars. - Classiq
Clint Eastwood wore the same boots that he did in Rawhide (1959). - IMDb user
Eastwood wears the same cowboy boots that he wore as Rowdy Yates on Rawhide, though the color cinematography of Leone’s “Dollars trilogy” allowed viewers to see the rich medium tan color of the roughout cowhide for the first time. These square-toed boots have slanted heels approximately 1¼” or 1½” high. - BAMF style
Boots that are somewhat similiar but not quite right.
Have a look at some of the various replica boots that can be found from makers around the world...