Picked up this 35mm Minolta lens which is the second version of the MC 35/2.8 line-up, the one with the hills-and-dales focussing ring. In Dennis Lohmann’s list it is number 72, type MC-II.
I hardly ever have trouble with oily diaphragm leaves with Minolta lenses in general, but these MC 35/2.8 lenses are the exception: all three are plagued by this issue! To be fair, I knowingly got those with this defect because they are primarily meant to sit in my collection; optically they are quite nice but offer nothing special over the later 35/2.8 Minoltas. The coatings are not as advanced as that of the MD lenses, so contrast is lower and sharpness is not as good either as that of the best MD lenses (quite some sample variation there). Some test pictures here.