My 5cm f/3.5 collapsible Elmar is the oldest lens in my stable, across all formats. It's an uncoated one made in 1945. I stand in awe of just how good this nearly 80 year old optic actually is. My Summicrons, Elmarit, and Nikon primes are "better" 35mm lenses by all objective measures, but there is something about that Elmar "look" that cannot be beaten. It has a particularly beautiful way of dealing with specular highlights giving the image a kind of beautiful glow.
My IIIf RD and 5cm Elmar are my goto "wandering around" pairing even though my prefered formats are 6x9 and 4x5.