I would get a room size de humidifier,firstly and clean and wax every square inch of that kit.When not in use,I would case them up,and use silica gel packets liberally inside the cases,to absorb ANY humidity trapped in the cases with thore drums.I live in Staten Island,and I'm about 4 blocks from the water,and at times,you can see the humidity.My drums and hardware are rust free,and I have no delamination of plys or wrap.:)
Steve B