I wouldn't have classed NCL as having a hefty throughput of freight. There are only 2 dedicated based freighters (Emerald with the HS748 and Air Contractors with the Herc), and they do nightly mail runs.
There are a number of ad-hoc freighters that drop in from time to time, but the frequency is fairly low. Some of the wide bodies that drop in may carry freight, but again the frequency is quite low, maybe only a couple a week.
In my opinion, there is a significant opportunity for MME to up it's freight throughput, especially as Teesside has a greater industrial concentration than Tyneside, particularly for the oil and chemical industries. I'm sure there is a significant demand there for time critical deliveries aceptable for air transport.