My friened has acquired 2.0 cm wievfinder I present on photos below. Russian 2.0 cm viefinders for Russar 2 cm looks are rectangles. This one is round and is made like Russian 35 and 85 mm viefinders.
There are some things which tells me it is Russian: - shape like 35, 85 mm - style of letters - coma bewteen "2" and "0" instead of point.
There are some things which tells me it is NOT Russian: - no Krasnogorsk logo on front - writing "F=2,0cm" above a rim not below like in Russian vievfinders - writing "N401" - no on Russian viefinders - "=" bewteen "F" and "2" - no on Russian viefinders
the style of the finder reminds me of german viewfinders custom made for makers like braun and exakta. but there are very few 20mm lenses, I only had a mir and a russar...