Not exactly what was asked for there but I thought I'd give a quick run through my thoughts on the Gemma spaghetti westerns I have seen.
A Pistol For Ringo - For me a classic of the genre, one of my top ten and I think one of the spaghettis that is of a quality equal to the Leones and that can be enjoyed beyond the genre audience. A great cast in stylish mix that is often both lighthearted and violent.
The Return of Ringo - Another undoubted classic in my opinion. Not much like the first film at all but fascinating and as spaghetti westerns go, pretty deep! The only flaw I can find in this film is that it gets a little two lighthearted at the end which jarrs with the rest. The same great cast as the first film but used very differently.
One Silver Dollar - Solid and enjoyable western, above average though it is somewhat traditional. I have not seen it in many years though.
Fort Yuma Gold - Very slow to start and the first half of the film doesn't relate very well to the second half but that second half is great! Some clever and fun scenes like the mysterious "accidents" at the bad guys hideout. I think Dan Vadis makes a great monster in this!
Arizona Colt - A Ringo film of sorts and a very good one. Classic Gemma.
Day of Anger - Very solid film teaming Gemma with another legend Lee Van Cleef. Some nice stylish flourishes.
The Price of Power - Fascinating on paper and the film sort of has everything but it does not 100% engage me I think I need to rewatch it. The director Valerii certainly pulls of some dynamic action and camerawork.
Ben & Charlie - A decent film but I don't think it makes the most of some of its ideas. Again I have not seen it in a while and must give it another look.
California - I'm not sure that it is a great twilight western. I need to re-watch it. It certainly has some good scenes and echoes Arizona Colt with "Michael Random".
Silver Saddle - With Fulci directing this is a strange mix of dynamic scenes of violence and cutesy kids stuff. I wish they could have made this as a more serious film.
I think these are all the Gemma westerns I have seen and reflecting on them I don't think there is really a bad film in the bunch. Not a lot of spaghetti actors can say they made some many good movies!