IMHO strip the dope from a completely oil free margin all around. Cut
away the oil soaked area (pay attention to any fastening methods. Clean the
structure thoroughly. Then afix Ceconite along the clean margin according to
the Ceconite manual, tighten with a steam iron and refinish with dope. Do
not try and wash away the crud from the Ceconite interior surface.

Barry A&P
..

My Decathlon is in annual right now, and needs some repairs to the
original
dope-on-Ceconite finish.
Our new A&P doesn't have much experience with fabric work, so he sought
advice from others. I'm feeling uneasy about the answers he got. A
couple
of questions for those with paint and fabric experience: