So, I sold the LNB, the dish, the modem and the controller back to Isatlan for £1200 and Ethnet replaced them all for just under £1,000.
I now have the F1 mount and new dish, new LNB, DW7000 controller and the HN7000s Modem.
Nick, the engineer for Ethnet got it working straight away.
Fingers crossed.