Uncoated post WWII Ja lens is web rumor. A CLE lens is unlikely to be the same glass as the glass catalogue changed, older glass was cancelled newer glass better IQ.

If you are using 400 ISO film for available darkness then a Nikon and a CLE won't be detectably different.

If you are buying without a lens the Cosina Voightlander 40mm f1.4 is available either SC or MC ie single or multi coated, in M mount. Later glass better IQ but not detectably different.

Lotta people prefer the single coated CL or CV lens. There is signature difference even when there is no visible flare.