The only real difference between the Zorki-3 and Zorki-3M is all the shutter speeds have been moved to the top dial. The shutter release button on the Zorki-3M also protrudes higher above its collar than it does on the Zorki-3. Most Zorki-3M's have a matt finish but there are some examples where the metal parts are highly polished [2].

   

Produced: 1954-1956
Name: „Зоркий-3М“
Producer: KMZ
Frame size: 24x36.
Lens: Jupiter-8  2/50.
Shutter: 1-1/25s, 1/50s, 1/100s, 1/250s, 1/500s, 1/1000s + B.

Quantity: 87.569 units (both with Zorki-3).

PM1355 - Zorki-3M  #5503332.

PM1355. Seems to be an earliest version of the particular camera. Finder's windows outlined by decorative rim. The four screws around the asscessory shoe. "Arrow" sign on the top plate (see picture below). Balance foot on the tripod thread. 

PM1360. Camera identical to PM1355, but without balance foot already. No otherwise different.

PM1355 - Zorki-3M  #5503332.

PM1365. Camera identical to PM1355, but without balance foot already. "Dot" sign on the top plate, slow shutter speeds in Red (see picture below).

PM1365 - Zorki-3M  #5564090.

PM1370. Camera identical to PM1365, but with additional "MADE IN USSR" engravings on the rear plate. Less common to find.

PM1370 - Zorki-3M  #5573884.