Advice please on how to test real order data (to check that it tallies correctly)

I'm building an ecommerce app (Laravel 5.3) that is replacing one I originally built in Zend.

The order data is being sucked in from the old app via seeds. These seeds are having to populate various new fields including an 'order_total' (which stupidly didn't exist in the old app) as well as fields like pre_discount_total and post_discount_total.

What I would like to do is run through the database to check the new figures all add up correctly. I started writing tests to verify the new totals but since these will have to loop through the entire orders table I'm having second thoughts about the best approach. I though it may be better to do this via sql directly on the db. The issue there is that I can't so easily share the tests with my colleague who is also tinkering with the new orders table and fields.

How would you go about this?

Example test:

 /** @test */
    public function is_vat_calculated_correctly()
    {
        $vat_rate = \Config::get('constants.VAT_RATE'); // UK tax

    // just plucking an order at random for now but was going to 
    // get and loop through all orders before I had second thoughts
        $order    = Order::where('customer_id', 690)->first(); 

        $goods_total = $order->goods_total;
        $delivery    = $order->delivery;
        $vat         = $order->vat;

        $correct_vat = ($goods_total + $delivery) * $vat_rate;

        $this->assertEquals($correct_vat, $vat);
    }