Freeing decals/transfers

My current WIP, the Miller Buick. The main hood decal (it would be the biggest decal there!) is stuck fast to the backing paper in one area.

It looks like something has been spilled on the backing paper and it's penetrated to the decal, holding it in place. 90% of the decal is free, just this one patch.

Any ideas? I was toying with the idea of wetting it again, and trying an eraser to rub through the backing paper.

Thanks in advance.

Chris

Only thing I can think of is to soak the hell out of it in hot water. 

When I do decals I put a small kitchen sponge in a container and sit the decals on the sponge.

Sorted. I gave it a good soaking, and with edge-of-the-seat suspense began using an eraser to slowly rub through the backing paper till I got to the transfer.
Only did the affected area, and it worked a treat, so the build goes on.

Good news, old decals can drive you mad.