At one time in the early '80s, I stripped asbestos and had to carry 50kg rolls of DPM polythene for creating enclosures. 8 of these on the roof, along with other equipment made the Merc 508D roll
like the naval vessels on which we often worked
.
My colleague and I decided in a quiet moment to lower the CofG by placing them under the floor [also, other teams never thought to look there when helping themselves to my kit].
We initially created a plywood platform hinged and suspended by nylon rope, and it worked well, apart from collecting road dirt, but the ply did stop most of it.
We then created ''soft boxes'' to snuggle up against the chassis and these kept everything clean.
Once this was successful, we then created more storage for much of the more robust items, including the grey water [never could stop the drain tap leaking once on the road], gas, clean water [in-built shower for decontamination] and other items.
With planning, it is surprising what can be stored, my '79 Bedford coach-built has had Dzus fastenings fitted to its skirts to enable easy access to the areas between the chassis and the outer bodywork. There is space for 2x100 litre gas tanks [releasing a kitchen unit sized space inside the body], spare wheel, tow-bar and 2 areas of around 1000x600 mm for storage lockers to take picnic chairs, etc. and more.
I have also replaced the black rubber rubbing strake on the lower bodyside with plastic conduit and run the renewed utilities through these, it saves grovelling under the thing sorting wires, camera feeds,plumbing etc., the conduit being 50x25mm. Oh, missing bumpers have been replaced using 100x100mm box conduit with enclosure plugs to seal the ends.
Of course, as with any additional storage, the vehicle's max weights and distribution must be observed.
Also, consideration of leisure clothing staying clean in adverse weather etc must be weighed into the equation when planning what to do, work clothes did not matter in the '80s :Tongue_Out_Emoji_wi
Hope this helps
Pete