Thanks everyone, you're right I should do a step by step guide... I used to work in a professional art gallery which taught me a few restoration tips. Maybe I should take commissions in return for bits and bobs missing from my collection! Let me summarise a week's worth of Y-wing lockdown night shifts in roughly 8 steps:
You have to loosen the glue from the sellotape and the box itself, flatten it out, then clean all the dirt and glue residue painstakingly, then reinforce it but taking care not to go too close to joins, flaps etc, leave under a press or weighted until firm, flat and dry. Where the cardboard has feathered apart you have to re-stick each layer with dry paper glue and weight until tight and flat (this is the slow bit, I use a pin to apply glue).
Once you're happy the box is clean, reinforced and structurally sound you can start the tidying up. It depends how far you want to go - I wasn't aiming for a 'brand new' box, I wouldn't recommend it. There's a lot of black to the design and my inks were a good match, so you can ink out every scrape, scratch, crease etc where white shows through the original black. You have to be careful to match and blend so it doesn't look patchy. Close up you'll see the box is worn, but without the white damage it looks good.
I didn't do anything to the artwork, but did touch up the Jedi logo red as I had a good ink pen match. Then you're ready to glue it. You can't really go back once you've glued the main seal. You need to do this evenly with the right glue, and weight enough to give a nice seal. Buff it down, use a light wax on a sponge to restore some of the sheen and protect.
No printing, no fakery, just old school techniques.
The main thing is not to rush it, and do it in stages. Be patient. Patience leads to concentration. Concentration leads to restoration...
PM me with any requests!