Instead of Crown use Macpherson and instead of Dulux use Glidden that's they're trade ranges e acrylic the same paint in different tins, I used to sell paint for a living before I retrained so have visited both companies for training and seen the factories of ICI. As for alluminium wood primer it is a very good product but does depend which top coat your using, I would never recommend it under a water based paint, that's not to say it hasn't worked for others but the odds are against you. One last thing if you do opt for tha ally primer make sure you don't ever shake the tin, always stir it and keep it stirred whilst you use it, but it is a suspension of alluminium and I shaken can become volatile and explode. To highlight the point a colleague of mine was going to paint the old warehouse doors one day, they were painted with a lead based paint some twenty years previous so he chose ally primer to block the less paint, as I said we were in a paint store so he decided to be lazy and chuck the tim in the mixer to save time stirring after 10 seconds or so he managed to blow the door of the machine and paint the manager, several thousand pounds if stock and a quarter of the shop silver.