Did you put some lubricant or anti-seize on the bushes when you reinstalled them Aldo? It's more likely to resist seizing again if you do. There are various lubricants different people use for that kind of application. If it is in a fairly hot environment, which I think that clutch is by the look of it, I use Kopr-Kote for that kind of job, but I don't claim to know it is better than fifty other substances. At room temperature I often use graphite grease because it seems to resist water penetration fairly well, but I think that clutch has been getting hot. I notice the car manufacturers tend to use a strange black substance with unbelievably small glass beads in it, for screwing exhaust manifold oxygen sensors in so that they can be removed years later. I know Kopr-Kote doesn't do all that well on exhaust manifolds, which typically glow red at full power.
