Identify a camera

[Mablo]

What is the camera the well known Argentinian doctor is using in this photo?

 

[Greyscale]

Zenit 3M with a Helios 44 2/58?

 

[Roger Hicks]

It looks surprisingly like an M with Viso and first-generation 90/2 in short mount, but it's very slightly too small to see.

¡Viva la Revolucion! (Now that it seems to be going in the right direction after some decades of stalemate.)

Cheers,

R.