The final step in the Dan Armstrong refinish was to paint the cavity behind the pickup rail matt black. So I masked off the guitar and sprayed.
And when I lifted away the masking tape a few hours later, it lifted the new nitro-cellulose off with it.
Lifting away the masking tape took the finish with it
I'm beginning to feel like Unlucky Alf from The Fast Show whose catch phrase was a resigned 'Oh bugger'.
It's only cosmetic
On the up side, by the time the guitar was reassembled you could hardly see it, honestly. And it certainly looks the way I intended.