I'd hazard a guess and say colour matching is going to be nigh on impossible because it looks like the paint on the rest of the car has deteriorated, it might be worth trying to polish the whole thing after painting the tailgate, with a rotary polisher.
Thanks for the advice. To be honest, I don't particularly care if it's not 100% match; if (when) I sell it on, the buyer should be anticipating doing a bit of work to a 23 year old van.
I'd hazard a guess and say colour matching is going to be nigh on impossible because it looks like the paint on the rest of the car has deteriorated, it might be worth trying to polish the whole thing after painting the tailgate, with a rotary polisher.