Richard,
I recently stripped the covering off a "Free" plane (see the building
section).
Here's how it went, soak paper towel with acetone, wipe, repeat. After three wing panels and a qt. of acetone, I discided to try my heat gun and it soften up the covering/adhesive enough to pull it off easily. DUH!
So, I'd suggest you try a little heat and then (If that fails) use the acetone/paper towels.
Good luck, Jerry
PS: Let us know how it went. OBTW; corn starch with the acetone will remove most of the oil.