FE2 with oily looking curtain?

I just got another FE2, looks amazing from the outside but then I opened it and saw that the curtain looked somewhat oily. Side note: could it be the isopropyl I used to clean the mirror that somehow could have caused this? I should have waited more than 10 mins but the itch was stronger so now I have a Portra 400 inside. I guess I will have to wait and see or simply develop the roll hahaha

looks ok to me.
I recommend not messing with it.

I've seen shutter curtains with worse problems, but nothing like this on Copal blades. Might of been someone just touched the curtains with a greasy finger.
I wouldn't worry unless it gets worse, of you have strange splatter marks on the emulsion side of your film.