info at: www.cameraquest.com
look under camera profiles "M lens guide" or www.kbcameras.com
for differences in various versions.
All cron 50s are good, from collapsible to modern(hooded). The only difference is in progressively higher contrast levels from older to new lenses. I don't know which specific lens you are refering to, but once you determine which it is, you can search for it in RFF gallery, flickr.com, or pbase.com under: 50mm, rigid, DR, summicron 50/2, any of those combinations will get you the sample images.
you really can't lose with a summicron if the price is right