Having re escalated your issue to the Places Team they have come back with the following response.
At the moment, we are not supporting businesses without permanent customer-facing establishments that have verified their business through the Google+ platform. By verifying a Google+ page in the Local category through the Google+ platform, that allows the page to display on Google Maps just as a listing verified through the Google Places platform does. However, at the moment, we do not currently have all the functionality of Places to indicate service areas and hide addresses when a business does not have a customer-facing establishment. Therefore, we ask that users with businesses like this maintain their listings on Maps within the Google Places account. You don’t have access to all the social features of Google+ for listings on Maps — yet. Soon we’ll make it even easier for you to take full advantage of Google+’s social features and manage your listings on Google. Look for updates on that in the coming months."
Unfortunately, we can't edit the Google+ address to mimic the Places account. We are simply just not supporting those types of businesses that have verified their listing through Google+ as the full address must be entered in and cannot be hidden because there is no option to do so.
When their listing comes back, it may look like a fully verified page, which will mean that it will show the full address and the whole issue in the beginning with their listing being down will happen again. The best option would be for them to let us know when their listing has come back so we can unverify the G+ aspect of the page and ensure it's just a Places listing.