Quick update: I was sick of seeing the peeling lacquer on the boot lid, and water was getting underneath it, making it worse and the affected area larger as the days went by. As we had a bit of sunshine yesterday, I decided to try and apply a temporary fix to the area, but I should have left it until I had the right tools really. I sanded it back with 600 grit, which was all I had, masked it off with note paper and sellotape, then gave it a coat of primer, then some AJ4, then some lacquer. It looks awful, really bad, but at least it's sort of protected until we can take it all back and respray that part.
Actually I say that, but when removing the masking paper, the tape pulled a nice strip of lacquer from just above the driver's side tail-light, so really I should have just left it. This just goes to show that you should always use the right tools for the job and never rush things. I'll try and get a photo up later on.