Do have a plan b.
Sometimes things don’t go to plan – like election campaigns with Theresa May as your frontwoman.
However if things don’t go to plan when setting up at a trade fair – say for instance you presume you’re allowed to bash nails into the walls of your stand when you’re actually not – then you can still come out on top if you think fast... Or even better, get someone more competent to think fast for you. (Especially if you yourself are armed with a hammer and preparing to flout the rules in panic).
So how exactly do you mount display shelves and a company logo on a wall entirely nail-free? The solution to your problem here is industrial-strength Velcro. Genius, right? All you need is to find a nearby art shop stocking the stuff, and then heavily rely on said competent person assisting you in the assembly of your new shelving. Simple. Like it was the plan all along.
And here’s proof that almost anything can be Velcroed to the wall...