The accursed decal sheet is Flightpast FP44-212. I did a quick search on Google and couldn't find anyone to complain to but fortunately I had made a high resolution scan of the decal sheet, 'just in case'. (This is something I try to remember to do after some previous experiences.) I can then print out the decals onto a blank piece of decal paper and use that but the copy is never as good as the original. Still, in cases of dire emergency, it's the only solution. As you can see, the reprinted decal is not as dense and therefore not as dark as the original, I'll try laying another copy over the top to get a denser colour but I'm not hopeful of my ability to match them up precisely and worried that two decals on top of each other will end up being too thick. We will see.
I gave the original decal sheet another thick coat of varnish in the hope of being able to use what was left on the sheet. However, while the white tail code worked okay on one side the decal on the other side blew up again. There's not much I can do about that.
As a famous author once said, we start off planning to write the equivalent of a gothic cathedral and end up with a mud hut. That's what this one is turning out to be.
I'll let everything set thoroughly for a day or two and see if I can finish off with something that doesn't look too bad.