First up I solved the issue with the AA guns, they now stay in position when level:
I then knocked up the fuel tank to sit behind the Mek Shed. This is the Mk. II version as I didn't like the first one I started.
On the right you can see the magnets the tank sits on and also the coiled fueling pipe the grots use to refuel the Koptas. Still need to work on the end (which would go in the Kopta) as it looks a bit naff.
With the fuel tank and KFF in position the end corner now looks like this:
In the rear shot above you can also see that I have gone round adding the edging strips along the decking. I also added a bit of plating to the deck to give more walkway space for the Grots to walk along.
Couple of pics to close on:
I think next i'll look at the decking before moving onto the walkways.
Something I forgot to add to the 'to do' list was I still need to add the track, but i'll leave that hassle till last.