I'm looking at these on ebay and both both lens have small defects. I'm just wondering if anyone thinks they would affect the performance and image produced?
One lens has a mark from where mould was cleaned off and the other has small dust speckles inside the glass.
Dust is really nothing, all used lenses have some type of dust inside, if
your lucky sometimes you can get one without, the mold spot is another
issue it depends how well it was cleaned out. Price wise I don't know
enough about those lenses to know if there a good deal enough, at least
there's a return policy on them.
Neither the dust nor the the small fungus removal spot will affect performance. However, especially the latter might affect the resale price, so I would only buy if that defect is discounted in the price quoted (you probably know the prices for Mamiya 7 gear better than I do, so you will have to judge that by yourself).
Like others said, dust is for all intents and purpouses no issue AT ALL. Even under scientific test, I am sure you wouldn't see the effect of that amount of dust in a lens. Even if was double that amount I am sure you would see NOTHING.
The mold though I have no idea about.
Like joeswe said, only effects a photographer psychologically (not practically) and effcts resell value, i.e hopefully you'll get it a bit cheaper because others will turn their noses up.