I used a spray can of Rustroliums gloss grey from B&Q. Looks a bit better than flat grey. If you have a T4 engine I think there is scoop for doing something quite different with it.
Mine was grey, but was painted pastel white to match the rest of the interior when the van was resprayed.
It looks nice Birdy but why not just get a can of the right colour from halfords, which is enough to do the panel and all the other grey bits in your bus and dries in a few minutes? ??? I'm not a fan of spirit based paints, they react with everything else. For someone like me they are the spawn of the devil.
I love oil based paint but its not good when time is money and theres a certain knack to using it Degrease with white spirit and let it evaporate fully and you dont get a reaction It is a time consuming paint to use but for the diy restorer doing bits at a time its very good value for money and leaves a very durable and glossy finish
...Just don't slap it on the body shell as a stop-gap thinking you'll get a pro to paint it later. It will mean the shell will need to be bare metalled and cost you many extra £'s. If you bought one like that to me I'd simply refuse to consider quoting and I'm in a majority here.
Where's mini bungle with his roof picture? I agree it gets a great finish, I just look further down the line.