This blog post has some sample photos with a collapsible 5cm f2 summicron that looks like it's from the same era:

https://talktog.wordpress.com/2013/08/15/lens-review-leica-l...

I have some lenses (Nikon 35mm and Pentax 55mm) that are identical other than having single-coating (thoriated glass) or multi-coating (non-thoriated glass).

The multi-coated versions all have a little bit more saturated colors. Other than that I have never noticed a difference.

I have a Nikkor 35mm f/1.4 with significant yellowing from the thoriated element. Apart from the yellow cast there’s no effect:

https://www.flickr.com/photos/gerikson/tags/35mmf14n/