Bob, thanks for the kind words. I aim to please
Gus, I've got some good news and some bad news.
The bad news is that, yes, it's a bit of a dog (although not an overpriced one). The good news is that you can teach it some tricks
The top is insulated, right? Two layers of metal, something in between? When the oven's running, the top exterior isn't incredibly hot, right? As long as it's insulated, you should be in good shape.
I compared the energy output to other pizza ovens and they match up, so you've got the power. What you don't have, that every gas deck oven has, is deflection- a way of taking the heat past the stone and up and over the pie- without superheating the stone. I'm also not terribly happy about the 270C peak temp, but there may be some ways around that.
I've come up with a homegrown approach to mimic commercial deck oven thermodynamics here:http://www.pizzamaking.com/forum/index.php/topic,21503.msg217026.html#msg217026
Before you try that, though, see what kind of heat balance you get just by putting the firebricks on the top shelf. Make sure the only thing in the oven is the firebricks. Regardless of the advertising photos you see, this oven will never bake multiple pizzas at a time- unless you want deprived oven spring from long bakes.
The top shelf position for the bricks will extend the pre-heat, but other than that, it should help even out the bake, both on the top and the bottom of the crust. How long are you pre-heating for now?
The oven thermostat is usually located in one of the top corners, can you see if you can locate it? It's usually a long probe.
An IR thermometer is really critical for this kind of oven for confirming stone temps. They're really cheap from Hong Kong. Let me know if you need a link.
If you can, find out the brand of the flour, or, at least, the protein content, as the protein content dictates the quantity of water to use. How does the dough feel when you're working with it? A bit droopy, a bit taught or just right?
You've got a broiler in the kitchen? What are the shelf dimensions there?