I haven't had a chance to check out the boot/s around the shifter yet, but I did start the car up today (as it is not registered yet as I am about to move house, etc) and when I jumped in it I could smell gearbox oil.
I assume this is a good indication that the boot/s are fitted incorrectly, or not seated properly, etc.
When I investigate more, I will report back here.
Thank you for all your help guys.
Cheers,
Dan