Our products typically arrive at completely different times so it is easier for you and us if you place orders for only product category per order. Different liveries of the same product are absolutely fine on the same order.
You will pay the same P&P charges if you place two orders for eg 2 x Class 92s (first order) and 1 x KFA container flat (second order) as if you placed the 92s and KFA on the same order.