Hi Gazza,
Please can you add a category for die cast under the category Toys & Hobbies, i think this could also have the subcategories Aircraft, Cars and Motorcycles.
I think it would be best located like this,
Toys & Hobbies/Die cast/Aircraft
so the others would be located like this
Toys & Hobbies/Die cast/Aircraft
Toys & Hobbies/Die cast/Cars
Toys & Hobbies/Die cast/Motorcycles
Thanks,