Apologies for not spotting this comment earlier. Funnily enough I was thinking today that if I were to move it on I might be able to squeeze a double bass into the spot it currently occupies...
I'm not really sure about value, but I would guess that £250 for the guitar plus £500 for the work would give someone a vintage Gibson at a reasonable price.
There's certainly a sentimental value attached to it but whether that's worth using up limited storage space is another question.