depends, There are ways to clean them but you need to find out what sort of prints they are. Some prints were also coated with a lacquer, and you would need to find out if they are, and what sort of laquer.
In the meantime some cotton buds and a very gentle rub may bring on marks, but be careful that you do not bring of some of the actual print emulsion as well.
The people who make pec-pads (those white pads used to clean sensors etc) also make an photographic emulsion cleaner called Pec-12 Photographic Emulsion Cleaner, you could try and source some of that and follow the process recommended for using it. (disclaimer, I have not used it, or know how effective it is, I just know the product exists and you use at your own risk)
https://www.vanbar.com.au/catalogue/...t.php?id=60304