..no. Not on those very old engines like the one above.
I do have the 2.5ccm Diesel from this Picture:
and three are no parallel grooves on the prop driver.
MVVS experimented a lot with different Intake mechanisms, for now
I don't know any mebrane type but all others in different forms :-)
For the overall finish look here:
..there are differences and some roughness is possible if it is a really old engine.
Last but not least: I don't know butI think it is an MVVS.
Maybe the TO can provide more pictures?
Never saw a russian engine with that kind of bulge.
I have other older russian Engines ("Polet")
that are .29, they are looking totally different.
Another occurence on the net