Puzzles... but no solutions

Here's the dilemma that's been at the top of my mind over the last month or so.

1. Campbell only eats fifteen different foods.
That sounds like a lot, but it's really pretty limited for a nearly four year old. Here's the entire list Pasta, beef sausages, ham, cheese, vegemite sandwiches, apples, watermelon, cereal, milk, sultanas, crackers, chocolate cake, yoghurt, icecream, tomato sauce. (You'll notice no vegetables...)

2. No wheat, no milk
Campbell is autistic. Something that helps autistic children a lot is a diet that is gluten and casein free. That means, no wheat, no milk. It's because their bodies don't digest the proteins well enough and they go up to the brain and act like morphine, drugging them out.

The wheat bit is easy enough to substitute, even though everything tastes a bit dodgy. The milk part is much harder to substitute. There are soy milks out there, but see point 3 for the problem with that. From the list then, here in italics is what has to be modified if I follow this diet:

Pasta, beef sausages, ham, cheese, vegemite sandwiches, apples, watermelon, cereal, milk, sultanas, crackers, chocolate cake, yoghurt, icecream, tomato sauce.

3. Low copper, high zinc
Another problem he has is his mineral levels are out of whack. He has incredibly high copper levels and really low zinc in his body. This causes 'undermethylation' of the brain and autistic-like symptoms. So he's supposed to avoid foods with copper in them. What's got copper in it? Well, ham and pork for starters. Then dried fruits and chocolate and soy. So if I substitute milk for soy, I'm pumping copper into his body.

So once I remove the foods high in copper, we're left with this:
Pasta, beef sausages, cheese, sandwiches, apples, watermelon, cereal, milk, crackers, yoghurt, icecream, tomato sauce.

4. ADHD and salicylates
As well as autism, Campbell has a touch of attention deficit hyperactivity disorder. The diet they suggest for that is different from the autism diet. This one takes away all preservatives and colours and foods with salicylates in them. Out of his diminishing list, we must remove apples and tomatoes and sausages.

What am I left with that he'll eat?
GF pasta, GF bread, butter and jam, watermelon, GF cereal and GF crackers.
Cheese, milk and yoghurt are not recommended but I can't find a low copper alternative.

And when I say 'he won't eat it', I'm talking loud screaming if it's on his plate, running away from the table and hysterics.

I wish I'd studied nutrition at uni! I'm doing a crash course in it now.

Any brilliant solutions?