Upper Front Inner Wing Repair

Before I fit the wing, I want to make some sort of panel to bring the inner wing and door pillar up to the wing.

I am not sure how this would have been originally, but as the wings and the top 6 inches of the inner wing were replaced by someone previously, I must assume this was just left.

At the same time, I may close up the petrol tank filler hole and breather pipe as the car came with a tank that is filled from lifting the bonnet.