Well in the end I unbolted the frame (8 bolts) re used four stainless threaded bar and bought four more to replace the four mild steel ones.
Wire brushed the frame and spray Hammerited it black. 4 coats used up two tins.
Bought the harder wearing Protectakote UVR kit and some Xylene thinners and chose dark brown as it was £34 cheaper.
Bought two black drip trays 600x1200 £32 the pair, which almost perfectly fit between the tank and the back doors and between the wheels arches.
One reel sits in a high sided wooden tray I had previously made so I can lift the reel out if necessary. This is screwed through one tray through the floor with four self cutting 10mm bolts/screws.
The other drip tray is loose but typically it has my safety cones, trad bucket and gear and a box of handy tools and spares in it.
On top the 650L tank ply cover out of the passenger side is another reel with a smaller drip tray, also my spare wheel and leisure battery. Pumps are now on the passenger side of the tank leaving room on the driver's side for my extreme 47 diagonally down the side of the tank.
Extreme 25 and 20 in drainpipes under the roof with a 2 metre pointer ladder between.
Small downstairs pole (old SLX top two sections cut to about 4ft) across the bulkhead.
Immersion at the back of the tank down low facing the back doors.