Another solution, Master lock sells a “lock box” similar to what Realtors used to use, it has a settable combination holds several (like 6) keys. You can lock it to the chassis, like in the engine compartment, and you will also always have keys. You can also use it if you drop the coach somewhere after they close/before they open and leave them the keys locked in the box, Just call them with the combo, then change the combo the next time you use it.
Dave, Bobbi and Fenway
2005 38' FDTS Alpine Limited, 2016 Jeep Grand Cherokee Limited
Lake Wales, FL