The 24hr citric acid / R.O. bath appears to have taken care of the mild surface rust and hard water staining. It did leave a black greasy substance on the spring. Soap scub rinse a wire brush to finish it off. Calling this a success ready for another 50 years.
Spring shows mild pitting exaggerated in the photo. Also presents remarkable strong tension and thick coil gauge for usage in a small machine requiring its 28cm long lever. Wonder about the designer intentions for a strong spring able to produce high bar requiring a finer grind.
Between order and chaos there is espresso.