If your that concerned, what about removing the valves and springs, bagging them up in a ziplock bag(s) and placing the bag in the case with horn. A couple of years ago, I was helping a friend sell her father's trumpet and that's the way it was packed away in storage for years. It was simple, I just oiled up the valves and greased the slides and it worked flawlessly.
Euphs:
Miraphone 5050 Ambassador
Wessex Travel (Tornister) Euphonium 'Maly' ER154
Yamaha 201 Baritone
Mp: Wick SM4 Ultra X
Groups:
The San Diego Concert Band