That's very good client service from KEH! Just to add to the others' voices, one of my all-time favourite lenses is a Mamiya Sekor-C 65mm f/4.5. This lens does not have one or two scratches, it is
badly scratched with many, many scratches of all sizes. I got it because somebody basically threw it away. It looks rough.
It is one of the highest-performance lenses I own, and it is
particularly resistant to flare or ghosting, better than even my mint, modern Schneider-Kreuznach APO-Symmar 150mm f/5.6 that I use on a Linhof 4x5in. I can point it straight into bright sunlight:
In short, don't worry about it. The zuiko 35/2 is also
particularly flare-resistance, when tested in the late 1970s it beat every single Leica lens for flare-resistance. I really liked mine:
Enjoy!