u/IAmNotAPillow

Hi everyone, first time I got used furniture and this sofa mattress came from a friend. I haven't seen any bugs, harborage, etc. but there were these stains I found which has made me very worried. I wasn't able to find similar pictures.

I did wipe everything down with alcohol and have it placed in my spare room with a diatomaceous earth perimeter for now. My friend said it was stored in a climate controlled basement and they had no history of pests.

Based on these stains, does it look like bed bug stains? Some look quite large and I'm hoping it is just oil from a folding mechanism or something. Thank you so much in advance!