In addition to Ferroni and Gemma the three films have in common Nello Pazzafini and Benito Stefanelli, composer Gianni Ferrio and film editor Antonietta Zita.
Stefanelli, just like on many other occasions (for example Once Upon a Time in the West, Day of Anger, Cemetery Without Crosses and Kill the Wicked!), is also credited as fight arranger and stunt coordinator on Fort Yuma Gold and Wanted.
Un dollaro bucato was written by the "Two Giorgios" Ferroni & Stegani (also assistant director), the 2nd had no less than six credited writers while Wanted had two scriptwriters and three screenwriters including Fernando Di Leo.
One Silver Dollar was fourth in 1965 Italian Box Office, obviously behind For a Few Dollars More but outperforming both Ringo films.
Fort Yuma Gold was ninth in 1966, behind The Good, The Bad and The Ugly but preceding Arizona Colt and Django, the latter penalized by the VM18 rating (until June '72, when a 2nd release was rated VM14).
Although in my opinion lesser, also Wanted was 26th among most successful SWs in Italy.
The American title Blood for a Silver Dollar contradicts the story, while for the 2nd film Fort Yuma Gold is not spaghettiesque at all but certainly more pertinent than the Leone-derived original For a Few Extra Dollars.