I believe if the Jeep has a valid US title, NOVA etc then it does not need the MVT to verify it but the DVLA will inspect to to check the numbers etc.
It’s worth buying all your paint at the same time to ensure it’s all the same shade. I didn’t do this, but did mix together all the 1 litre tins in a big bucket and then put it back into the smaller tins to make sure they were all the same colour.