PB, Bob's assessment of your tomatoes is on the money. I've worked with a few UK purees and passatas and, unfortunately, they tend to be darker/more cooked then their equivalents across pond. When they're dark like this, they get sweeter (and brown faster), but they also lose their bright, fresh flavor.
Whole tomatoes bashed with a hand blender will generally give you the freshest flavor, but... they'll have a tendency to be packed in a very watery juice, so you almost always have to pour most of the juice off to end up with a good consistency sauce. This can lower the yield and make them costly. Your finely chopped tomato option (again, hand blended for a bit) might be the best choice, but I'd go the whole tomato route once or twice so you have a clear idea of the bright flavor and bright red color that you should be looking for. If the finely chopped tomatoes can't match the color flavor of the whole ones, then you might need to stick to whole or find finely chopped tomatoes (or crushed) elsewhere.
The pies are looking much better (congrats), but the crumb is looking a bit dry, and I think you can dial back the thickness factor a bit. Plug your figures in the dough calculator using a thickness factor of .085:http://www.pizzamaking.com/dough_calculator.html
and copy and paste the final results here. Once we see the percentages, we can perhaps adjust the water (hydration) and get you a little more moisture in your crumb.